iii ii ii V, i'R mn IM^ 11 iiii iHilliHliHliil'lilHi ®I|g ^. p, ^m plirarg }L^ QH5IT Hag, rty of ;alf NORTH CAROLINA STATE UNIVERSITY LIBRARIES S00961003 J Date Due <". V - . » ^ FeblO's:? ^ in 1 u # r / / / y ^^(^5 1 / LABORATORY PROBLEMS IN CIVIC BIOLOGY BY GEORGE WILLIAM HUNTER, A.M. HEAD OK THE DEPARTMENT OF BIOLOGY, DE WITT CLINTON HIGH SCHOOL, CITY OF NEW YORK AUTHOR OF "elements OF BIOLOGY," "ESSENTIALS OF BIOLOGY," "a civic BIOLOGY," ETC. AMERICAN BOOK COMPANY NEW YORK CINCINNATI CHICAGO Copyright, 1916, by GEORGE WILLIAM HUNTER. All rights reserved. HUNTER LABORATORY' PROBLEMS. W. P. I DeMcate^ TO MY PUPILS WHOSE INTEREST AND ENTHUSIASM HAVE GIVEN RICH SUGGESTION FOR THE CONTENTS OF THIS BOOK 19651 CONTENTS Foreword to Tkachkks I. Directions to the STri>ENT for Keetino Notes in 15i<>i.o(.^ =„->x>TT.», II' The Environment of Plants and Ammai.s 1. To determine the factors of envirouiuent .... 2. Comparison of a natural with an artificial environment 3. To test my home environment ...... 4. To learn the conditions of my city environment . 5. To determine and to illustrate by a graph the changes of temperature (one of the factors of the environment) during a given day 6. To make a graph to show how much fluid I take into my body in a (hiy 7. May environment influence public health ? . III. The Interrelations of Plants and Animals 8. A field trip 9. How to know an insect 10. To learn to recognize insects that frequent flowering plant.s 11. To study the life history (metamorphosis) of an insect 12. To learn the structure and work of the parts of a flower 13. The cross-pollination of flowers ..... 14. To study cross-pollination in butter and eggs 15. Special directions for the study of some fall fli>wer.s (Kxtra) 16. To find other pollinating agents besides insects . IV. The Functions and Composition oj Livinc Thing 17. The uses of the parts of a plant 18. To study the needs and uses of the parts of a living animal (Study of compound micro.scope) 19. To determine the unit of structure in plants and aniiiials 20. To determine some of the properties of protoplasm 21. To study structure and growth of pollen 22. To study the reason for the growth of polk'ii grains in flowers 23. To discover how fruits are formed .... 24. How and why fruits and seeds are scattered r \i.r. 13 W) • *•» — • t •Jl 28 30 30 32 ;i3 :I4 34 '.H\ 38 ;v.» JO n 43 •10 i<; i: t: JO .-.0 r.i :.i r.2 53 CONTENTS PROBLEM V. Plant Growth and Nutrition. Causes of Growth 25. To find the relation of tlie embryo to tlie food supply 26. To test for starch 27. To test for grape sugar 28. To test for fats and oils 29. To test for proteins or nitrogenous foods 30. To test for the presence of mineral matter (Optional) 31. To test for the presence of water .... 32. To test various food substances for the organic nutrients (Home work) 33. To show how much water is needed to make a seed germinate (Home experiment) ........... 34. To determine the temperature best fitted to cause peas to germinate (Home experiment) ........ 35. To show that seeds need some part of the air in order to grow 36. To show that food is needed by the embryo in order to grow 37. Is any part of the air necessary for combustion ? (Demonstration) 38. To test for oxygen (Demonstration) 39. To test for carbon 40. To test for carbon dioxide 41 . To prove that organic substances are oxidized within the human body 42. To prove that growing seeds oxidize food .... 43. To study the fruit of the corn plant 44. To study the structure of a grain of corn . . . . 45. To find the use of the endosperm of the corn grain 46. To find whether starch or grape sugar will dissolve in water 47. To find how the young plant makes use of the food supply. Digestion 48. What changes take place in starchy foods in the mouth ? (Demon stration) ..." 49. Conditions necessary for the action of diastase . . . '. 50. What is the reason for digestion of starch in the corn grain ? PAGE 55 56 57 57 58 58 59 60 00 01 62 62 63 63 64 65 65 6Q 66 67 67 67 68 68 69 69 69 VI. The Organs of Nutrition in Plants — The Soil and its Relation to the Roots .... To find out the structure of roots ....... To determine the influence of gravity on the direction of growth of roots ........... To find the effect of water on the growth of roots To study the structure and purpose of root hairs 55. To discover how fluids travel through roots and stems 56. To find out how root hairs absorb soil water .... 57. To determine what kind of substances will pass through a membrane 58. To test organic material in soil ....... 59. To find what kind of soil holds water best 51 52 53 54 72 72 73 73 74 74 75 76 77 77 |'a<;k 78 7H 79 80 80 84 85 85 CONTENTS PROBLEM 60. What do plants take out of the soil ? 61. How are root hairs able to take mineral matter out of the soil ? 62. What are root tubercles and what is their use ? . 63. What is crop rotation and what is its use ? . 64. What roots are useful as food ? VII. Plant Growth and Nutrition — Plants Make Food 65. To prove that water is given off by a green plant 66. Through which surface of a leaf does transpiration take place ? . 67. To determine how the structure of a leaf fits it for the work it hius to do 86 68. To study the microscopic structure of a leaf ..... 80 69. To show the effect of light on green leaves .80 70. To determine the relation of light to the presence of starch in a green leaf 87 71. Is a part of the air a factor in starch making in leaves '.' . . . 87 72. The need of chlorophyll for starch making 88 73. To consider the leaf as a manufactory 88 74. To show that a gas is given off as a waste product when green phmLs make starch 88 VIII. Plant Growth and Nutrition — The CiRrri. \ti<>n wi. Final Uses of F'ood by Plants .... HI 75. Groups of plants told by the structure of their stems . 76. To study the structure of a woody stem 77. To prove that liquids rise through steins (Review) 78. To find out through which part of a woody stem food passes down 79. How plants with special digestive organs get their nitrogenous food 91 93 •>4 'M IX. Our Forests, their Uses and the Necessity kok thkir Protection ...... 90 81. To determine some uses of stems 97 82. To determine the value of certain woods 97 83. Museum trip for study of woods 98 84. To identify common trees by the use of a key 99 X. The Economic Relation of Green Plants to M*n . KX) 85. To determine the economic importance of sonu' green plants . . 1(M» 86. To learn to know some green plants harmful to man .... 1«>7 XI. Plants avithoft Cmlorophvii. in their 1?i:i.atio\ to Mvn 110 87. To determine the relation of fungi to the destruction of certain trees 111 88. To determine the conditions favorable for the growth of mold . .112 89. To study the structure of bread mold 112 8 CONTENTS PEOBLEM PAGE 90. What is fermentation and what causes it ? 113 91. To learn to recognize yeast phmts under the compound microscope . 114 92. Do yeasts grow wild ? 11,5 93. To determine the conditions favorable to the growth of yeast . . 115 94. AVhat are the conditions favorable for the growth of yeast in bread ? (Homework) . . . 116 95. How we proceed to the study of bacteria 116 96. How to prepare culture media ,.117 97. To demonstrate a pure culture 118 98. To determine where bacteria may be found 118 99. To study how rapidly bacteria grow . . . . . . .119 100. What foods are preferred by bacteria ?....., 120 101. What effect has heat upon the growth of bacteria ? . . . . 120 102. To note the effect of moisture and dryness upon the growth of bacteria (Home problem) .......... 121 103. To determine the effect of pasteurization upon the keeping quality of milk 121 104. How to care for milk bottles at home ....... 122 105. To determine the bacterial content of milk ..... 122 106. To determine some of the most effective preservatives . . . 123 107. To determine the most effective disinfectants ..... 124 XII. The Relations of Plants to Animals . . 127 108. To study some biological relations of plants and animals in a balanced aquarium . .......... 127 109. To learn what we mean by the carbon and the oxygen cycles . . 128 110. To find out the course of nitrogen in its relation to plants and animals 129 111. To prove a hay infusion is an unbalanced aquarium .... 129 XIII. Single-celled Animals Considered as Organisms 112. To study a one-celled animal in order to understand better (a) its reactions to stimuli ; (6) the cell as a unit of structure 113. Comparative study of various forms of single-celled animals to explain division of labor (Extra problem) ..... 115. To compare reproduction in plants with that in animals 116. To study the division of labor in tissues and organs . 117. To find some of the functions common to all animals . 118. How to know some types of animals in the animal kingdom 132 1.32 1.35 XIV. Division OF Labor. The Various Forms of Plants and Animals 137 114. How the plant kingdom is classified ...... 137 139 140 141 141 146 XV. The Economic Importance of Anijials 119. What Rnimal foods are cheapest in any locality and why ? (Home work) 147 CONTENTS 9 PROBLEM 120. How animals may benefit mankind 121. To find out bow birds are of economic importance 122. What are the causes of decrease in the number of birds '.' 123. To study tlie life liistory of the mosquito ..... 124. To find the breeding places of mosquitoes in any locality :uid liow t« destroy them ......... 125. To determine some methods of destroying mosfjuitoes 126. To find the relation of mosquitoes to diseases of man 127. To study the life history of the parasite causing malaria . 128. To study the life history of the typhoid fiy .... 129. To determine the harm done by the fly and the way it does this liarm 130. What is the best way to catch and destroy flies ? ( Home work) 131. To determine harm done by insects 132. To know some forms of animal life that cause disease XVI. 133. 134. 135. 13G. 137. 138. 139. 140. 141. 142. 143. 144. 145. 146. 147. 148. 149. Sttdy of The Fish and Frog, ax iNTRonucroKY Vertebrates . To determine how a live fish is fitted for life To study food getting by the fish To study the sense organs of the fish . 1 o study some of the internal organs of a fish lo study the skeleton and central nervous system of the fish (Kxtra Ilovv fishes are artificially jDropagated ...... Trip to the aquarium (Optional, in place of Problems 133 and lo8j To determine some adaptations in a living frog . Adaptations of appendages for locomotion . Adaptations for sensation ..... Adaptations for food getting .... Adaptations for breathing ..... Museum trip to study the frog group (Extra problem based on trij to American Museum of Natural History) .... To collect and study frogs' eggs To study conditions favorable for development of frogs' eggs To study the metamorphosis of the frog .... To work out a comparison of development of the vertebrates XVII. Heredity, Variation, Tl.vnt am> .\mm\i. HurKPixi; 150. To determine if there is individual variation in any one niea.'^ure ment of the members of a given class . 151. To show variation in a given class 152. Does heredity play any part in our lives :' . 153. To study the fine structure of an egg cell . 154. How selection is made . . . • • 155. A practical result of selection .... PAOK 148 148 149 119 l.'.l l.'.l 152 152 153 154 155 i:.5 153 HJ3 164 165 165 1«5.-, 165 nw; lu: \m 108 169 173 174 176 177 !> 178 179 10 CONTENTS 170. 171. 172. 173. 174. 175. 176. 177. 178. 179. 180. 181. 182. 183. PROBLEM 156. To determine some means of selection of fruit trees from the economic standpoint ......... 157. How hybridization is accomplished in flowering plants 158. Other methods used in plant breeding .... 159. To determine the working of Mendel's Law 160. To determine some means of bettering, physically and mentally, the human race ......... 161. Are good mental parts or qualities capable of transmission from parent to child ? . 162. Does control of our environment have anything to do with the prob lem of race betterment ?...... XVIII. The Human Machine and its Needs 163. To show that the human body is made up of cells 164. To find out some functions of the skin .... 165. To study the use of the muscles ...... 166. To study the structure and uses of the skeleton . 167. To find the relation of muscles to bones in the human body 168. To study the joints of the human body .... 169. To get a preliminary survey of the internal structure of the human body PAGE XIX. Foods and Dietaries How to determine the nutritive value of food The use of the bomb calorimeter (Optional) To find the value of food as a tissue builder compared with its cost To find the value of food as a source of energy compared %vith its price To find my daily Calorie requirement .... To find the proportion of protein, fat, and carbohydrate needed in my daily Calorie requirement ..... To obtain my daily dietary with the 100 Calorie table of Fisher and to make the necessary corrections in my dietary . To compare your day's total Calories with the estimated needs of a person of your age doing the kind of work which you do To find the relation of the value of food to its cost in the family dietary ........... To study some forms of food adulteration and some means of detect ing adulterants To determine the effect of alcohol upon raw white of egg . To deternnne the amount of alcohol in some patent medicines . To test for acetanilid and to know some patent medicines containing it What are tlie harmful materials formed in catarrh cures and soothing sirups? , . . , . 215 CONTEXTS 11 PROBLEM XX. Digestion and Ahsoimtmin . 184. To compare the digestive system of a frog with that <»f iiiai 185. To study my own teeth 186. To demonstrate the function and structure of a simple j;land 187. To find the use of digestion 188. To determine the conditions most favorable fur ga.siric digestion 189. To determine another effect of gastric juice 100. To note the action of pancreatic juice on starch . lUl. To note the effect of pancreatic juice on oils and fats 192. To study the effect of artificial pancreatic juice on i^rotein 193. To find one action of bile 194. To study the method and place of absorption in the human body 195. To understand the structure of a villus 196. How may foods be absorbed by the villi ? . 197. To find the pathway of absorbed foods XXI. The Blood and its Circulation 198. To prove that blood contains nutrients 199. To study the corpuscles of the blood .... 200. To determine the effect of oxygen and carbon dioxido upon tlu- 201. To study the structure of the heart .... 202. To study the circulation of the blood .... 203. To determine the rate of your own heartbeat 204. What is the effect of hard mental work on the pulse beat '.' 205. What effect has exercise on the heartbeat ? 206. How to stop the flow of blood in case of an accident . XXII. Respiration and Excretion 207. To compare the structures of the lungs of the frog and of man 208. To determine changes that take place in air in the lungs 209. To find the capacity of the lungs .... 210. To study the mechanics of respiration 211. To study the part the ribs play in respiration 212. What is the function of the diaphragm ? . . . 213. To find out what becomes of the oxygen in the lungs 214. To make a study of ventilation 215. To study air for presence of du.st (Home experiment) 210. To determine the best method of cleaning a room 217. What makes a crowded, closed room uncomfortable ? 218. To study the structure of the kidney .... 219. The skin as an organ of excretion and heat control XXIII. Body Control and IIauit Formation 220. How are we aware of the world about us ? 220 221 222 223 •JJ \ 224 225 225 225 22r, 226 blood 228 232 232 2:W 2:^4 235 2:}6 237 237 237 238 240 211 241 242 242 213 243 244 244 245 245 246 24«» 251 251 12 CONTENTS PROBLEM 221 • • To determine what parts of the body are most sensitive to (a) touch, (6) heat and cold ...... 222. To study the anatomy of the nervous system 223. To study the structure and use of neurons . 224. What is a reflex action ? 225. To compare the reaction time of hearing and toucli 22G. To compare a reflex action with an act of thought 227. To study habit forming 228. To study the mechanism of habit formation 229. To consider some harmful habits 230. How to go to work to form good habits 231. To determine the relation between taste and smell with reference to food flavors ........... 232. How to find out certain defects of vision in the laboratory 233. What are some of the effects of alcohol on the nervous system ? XXIV. Man's Improvement of his Environment . 234. How to ventilate my bedroom (Home problem) 235. To compare the duster and the dry cloth with the moist cloth in cleaning the schoolroom ........ 236. What should I eat for luncheon ? 237. To make a sanitary map of my own environment .... 238. To determine the bacterial content of different grades of milk . 239. To determine the bacterial content of some kinds of water 240. To determine some of the problems of water supply and sewage dis- posal for a city 241. Is typhoid a city or a country disease ? 242. What is the annual cost to New York city of some preventable diseases ?.......••.• 243. What are the chief causes of death in a city ?...-. 244. To study the relation of the death rate to the season .... 245. To find a relation between flies and mortality 246. To determine the number of school children who needed treatment for different diseases in New York city, 1914-1915 247. How to discover the presence of adenoids 248. To find some ways of preventing the spread of disease 249. First aid in the home. A summary of what to do and how to do it . PAGE 252 253 254 254 254 255 255 256 257 257 258 259 259 262 263 263 .264 265 266 267 268 269 269 272 272 272 273 274 274 277 FOREWORD TO TEACHERS It has become the fashion in modern pedai!;o^;y to teach by the so-called " Problem Method," that is, to attempt to make the child solve problems from the very beginning of his work in the elementary school. But it is one thing to say to the child, " Here is your problem, solve it," and quite another thing to lead him through the several thought processes necessary to the solution of the problem. A child of six may be taught to tliink, and think clearly, if he is guided so that he makes a generalization after comparison with what his senses tell him he knows. The mistaken notion of our educational system has been that (hill and drill alone, pure memory work, is only fitted for the mental life of our young children. Nothing is further from the actual truth. The mental growth of the child is an evolutionar}- growth, but it is a development based more upon his reaction to the world than upon the mechanism within his body. The nei-vous system and its connectives develop early. Our education of the nervous system, based on the theory that the nervous systeui is not well developed, makes simply for the formation of concepts. Concept forming and concept enlargement are a necessary jiart in any scheme of education, but the method and the form of straigiit thinking are of even greater importance. Problems in life are not solved by knowing dates or facts, no matter how inu)()rtant or interesting these may be. The methods of icaching a conclusion, of weighing evidence, of making decisions upon the merits of the facts in a case, of thinking straight from evidence gained from given data, — these are the habits of mind which iwv wortli far more to a child than the actual im])act with the subject matter in a textbook. Hence pure science, the handmaiden of clear N. C State ( 14 FOREWOKD TO TEACHERS thought, needs emphasis placed on method above all else. And the method of science is best found in the laboratory. Dr. H. E. Walter has well summed up the real use of laboratory work in the following words : " The laboratory method was such an emancipation from the old-time bookish slavery of pre-laboratory days that we may have been inclined to overdo it and to subject ourselves to a new slavery. It should never be forgotten that the laboratory is simply a means to the end ; that the dominant thing should be a consistent chain of ideas which the laboratory may serve to elucidate. When, however, the laboratory assumes the first place and other phases of the course are made explanatory to it, we have taken, in my mind, an attitude fundamentally wrong. The question is, not what types may be taken up in the laboratory, to be fitted into the general scheme afterwards, but what ideas are most worth while to be worked out and developed in the laboratory, if that hap- pens to be the best way of doing it, or if not, some other way to be adopted with perfect freedom. Too often our course of study of an animal or plant takes the easiest rather than the most illuminating path. What is easier, for instance, particularly with large classes of restless pupils who apparently need to be kept in a condition of uniform occupation, than to kill a supply of animals, preferably as near alike as possible, and set the pupils to work drawing the dead remains ? This method is usually supplemented by a series of questions concerning the remains which are sure to keep the pupils bus}'- a while longer, perhaps until the bell strikes, and which usually are so planned as to anticipate any ideas that might naturally crop up in the pupiFs mind during the drawing exercise. " Such an abuse of the laboratory idea is all wrong and should be avoided. (The ideal laboratory ought to be a retreat for rainy days; a substitute for out of doors; a clearing house of ideas brought in from the outside. Any course in biology which can be confined within four walls, even if these walls be of a modern, well-equipped laboratory, is in some measure a failure. Living things, to be appreciated and correctly interpreted, must be seen and studied in the open where they will be encountered through- FOREWORD TO TEACHERS 15 out life. The place where an animal or plant is found is just as important a characteristic as its shape or function.. Iiiipossihlo field excursions with large classes within school hours, wliich only bring confusion to inflexible school programs, are not necessary to accomplish this result. Properly achninistered, it is without doubt one of our most efficient devices for developing l)i()logicaI ideas, but the laboratory should be kept in its proper relati(jn to the other means at our disposal and never be allowed to degenerate either into a place for vacuous drawing exercises or a biological morgue where dead remains are viewed." Teaching to think is not a sinecure for the teacher. But by proper use of the laboratory material and the laboratory period, we may make a brave start toward this goal. One preconceived notion of a laboratory period is a time in which the pupil works alone from his specimen in order to interpret something which you and I know is there but of which he is ignorant. The metliod of Agassiz may be fitted for the graduate university- student, but it must be modified for the immature pupil of the high school. We must throw away our college and high school laboratory (5onception and place ourselves in the laboratory as a pupil. Be a leader in a discussion which will center around the specimens in the pupil's hands; present, in connection witli the laboratory material, some definite problems relating if possible to some phase of activity of the material in hand, something vital in the mind of the pupil. Lead the discussion (using the printed ([uestioiis that follow, but augment them with others that will naturally arise during the discussion) toward the solution of some definite phase of the problem in hand. ('Allow conversation among the pupils; get as many ideas from different pupils as you can; i)it the brighter ones against each other and the spirit of competition will incite the dull ones to add their mites. But guide the discussion toward a goal, — that is your function as a teacher. , Do not be afraid to tell when it is time to give information and do not be afraid to say, " I don't know." Ultimately the time will come, when the discussion of facts as pupils see them has reached the place when* a conclusion may safely be reached. Now is the place for the teacher, again for- 16 FOREWORD TO TEACHERS nuilalin^- the i)i()l)l(Mn, to give the class — this time as individuals — opportunity to write their generalizations, or their answer to the problem, in th(^ form of a good English sentence or paragraph. After this is done reading of conclusions by several individuals allows by comparison the fixing of the correct conclusion in the minds of all. Time is thus obtained for rectifying the tangled ideas of those members of the class less able to cope with the prol)lcm. Incidentally, this does away to a large extent with correcting laboratory papers, as the student, by comparison with the final corrected conclusion, does his own correcting. This makes for more effective science teaching, as the teacher of science should be a leader, not a drudge. Sometimes a generalization is asked for, perhaps before the pupil is ready for it, for the object is to incite the worker to be something more than a blind reader of directions and a maker of drawings. An immature conclusion — even a wrong conclusion — in the form of a generalization, is better for the pupil than contentment with no conclusion at all. If the child can be stim- ulated to think from the very beginning, then do not worry at first over the exactitude of his conclusion so long as he is trained in the making of judgments. It is the thought process we are after at first, the method of thinking more than the scien- tifically exact result. The latter will come gradually as the hori- zon of the pupil widens. We all know our concepts change. What is an exact concept at fourteen would not stand the test at twenty-four or at forty-four. It is a true maxim that experi- ence is the best teacher. Be that so, even experience does not make thinkers of us, unless we know how to profit by her teachings. Tlie pages that follow are intended to act as a guide and a stim- ulus to the pupil so that he will be led to see beyond the printed words in the textbook. Many children do not know how to use their text. Diagrams and figures mean nothing to them. The old-fashioned thought questions found in so many textbooks of twenty-five years ago were of great value because they crystal- lized the problem before the student and focused the attention on the essentials within a given paragraph. The pedagogic value of questions on diagrams is great. The use of graphs is a part FOREWORD TO TEACHERS 17 of every educated person's equipment in life. These fiicluis are strongly emphasized in the working out of the problems of this book. An attempt has been made by the author to be practical as well as logical, and to gain interest through the practical treatment of things that are familiar to the pupil. Whenever possible, techni- cal terms are done away with, and experiments are made as simple as possible without destroying their scientific value. In general, a few large group problems have been made that directly explain the text of the author's Civic Biology, which this manuscl is intended to interpret in the laboratory. In addition io these, other secondary but closely associated problems are added with less explicit directions, so as to give opportunity for some mental activity in their solution on the part of the pupil. It is not expected that all the problems are to be attempted in a year's course in elementary biology, but a choice should be made bj- the instructor of what he considers the most important for his own particular classes. The author wishes especially to thank Messrs. George T. Hastings, John W. Teitz, and Frank M. Wheat of the Department of Biology in the De Witt Clinton High School for their many helpful sug- gestions and for certain of the exercises and excellent drawings accompanying many of the experiments. All members of the department have in one way or another given ideas to tlie lab- oratory exercises which follow, and my sincere personal thanks are due to them as well. The author also wishes to make acknowledgment to the various sources from which the experiments and lal)oratory exercises of the following pages were adapted. Of especial value in this respect have been the numerous publications of the Department of Agriculture, the Bureau of Fisheries, and the various health reports of state and city Boards of Health. The Cornell Uni- versity Reading Course Pamphlets and tlieir Xature Study Leaflets have also been of much service, especially in the work on dietetics. In the laboratory study of dietaries the 100 Calorie Portion Table of Irving Fisher, comi)iled from the Journal of the American Medical Association, Vol. XL\TII, No. 16, has also HUNTER LAB. PROS. — 2 18 FOREWORD TO TEACHERS been useful. For the idea of the biological survey of a neighbor- hood, I wish to thank Professor Clifton F. Hodge, and his sugges- tive and inspiring Nature Study and Life. William H. Allen has kindly permitted the use of some of his excellent tables compiled in Civics and Health; to him I also extend hearty thanks. The arrangement of the laboratory problems, previously used by Mr. Sharpe and myself in the manual accompanying the Essentials of Biology, claims no originality except in application. The laboratory problem form was first worked out, so far as I am aware, by Arthur Stone Dewing in a manual prepared for the Knott Apparatus Company. This book adapts the problem method to young students in an urban community. The problem questions given at the end of each chapter follow the old and tried plan of summary questions given at the end of a chapter in a textbook for the purpose of bringing together the important points in the mind of the pupil. These questions are so formulated as to make the student use the material worked over in the laboratory, together with the additional information gleaned from the text, so as to reach definite and clear-cut conclusions concerning the essential points in the chapter just finished. Nearly every laboratory chapter has been prefaced with a few words to the teacher. These are important, as they serve to indi- cate the viewpoint of the writer and the philosophy underlying the various parts of the book. It is hoped that these suggestions may add clarity and help those who use this book to organize their work. LABORATORY PROBLEMS L\ ("1\ IC BIOLOGY I. DIRECTIONS TO THE STUDENT FOR KEEPING NOTES IN BIOLOGY It is suggested that two notebooks be used. In one, the home notebook, all written notes, either dictation notes or those looked up frorn original sources, should be placed. The other, a lal)ora- tory notebook, should be used for drawings and written work done in class as well as experiments and demonstrations performed in the laboratory. The illustrations on pages 20 and 21 will serve to indicate the appearance of a blank page after laboratory w jrk has been done. All written work should be in ink, and great care should be exercised not only in the construction of good English sentences, but also in writing. A careless, slovenly page may spoil otherwise excellent work. Especial care should be exercised in making your drawings. A hard pencil (HHHHH) sharpened to a needlelike point shouhl be used. Do not shade your drawings. Make each line mean something definite. We do not want artistic sketches so much as we want accurate representations of what ytni see. Uememl)er a good workman uses good tools; therefore use a sharp, pencil, a clean eraser, and an active hand and brain. Drawing witliout thought of what you are doing is only busy work and does you no good. Among the most important of your laboratory exercises are your experiments. An experiment should have four stei)s, each of which is separated from each of the others by a paragraph headmg. 19 20 DIRECTIONS TO THE STUDENT The four steps are 1, the problem ; 2, the method used ; 3, the obser- vations made; and 4, the conclusion reached. layn/. /S,l'^/6. (U/^ d/CuUyoiny 3a^ij das,t- VJAxrifU/yT^ lU^ AJUiA^y, '(MA^{/vn^ AJil/ijy /t^'^M-t^^ CAiAMxmy ycmy. (j/Jj-dlAyVx^Xumj : <:zJyKJO _AZjuL^ A^^^^ /O-mAy ^tAju AAyy-TnJX'LraJjAy rOtAAy Carved^. jJlAAU^ ZtA/xXj JjnJUL C/XAJj^JU JiurrUUAJ-tkMji^ Stxr- Xyn~ '^ JjxX- .Mjl^J.^ . Under the heading problem you should tell exactly what you are trying to solve ; your method should describe exactly how you went to work to set up your experiment and what you subsequently did ; the observations are what you saw (as a result of what you DIRECTIONS TO Till-: STKDIOXT 21 did); and your conclusion fihould ])v rcacluMl only after wci^iliinn the evidence you have obtained in your expcriiiicnt and ilicii aj)- o o /[^Ke StLcd^ of tlic'BeaTL sSeecL tei^k irvb "tKe, CjiOdtvo or k»ab^' pIcxJv-t ap-oL tKe- seeoL Cocxt or tjLstoL. c/ "LuJo Co'tyTec3LoJv5 , ■t}^Q> Xj^ po c oi-xl. . c3.eYG-Xo-Tos iTvto 't-ir^Q. r^oot oTvct stc,>^^. -^ ^tv^ aT\o"t}\e»~ ex ^eT- iTi^exu't 1 provG<^ "trvcx7~ 0"tjaT"C- IV OTV>, cTov-G, O. vci-'^ 'posture Qxl CL c5reoL$e. Spot. 5Ko>vm which it receives certain materials necessary for its life. What is your environment? Clive e.xamph^s of some diU'ereiit kinds of environments. (See Hunter's Civic Biology, Chap. IL) Explain the term '' factors of environment." 23 24 ENVIRONMENT OF PLANTS AND ANIMALS Home Work. — Determine the factors of the environment of a plant; of some wild animal; of a cat or a dog (domesticated animals) ; of 3^ourself . Bring to class a written statement of your answers. ' Having compared these different living things in their differ- ent environments, decide what factors are common to all envi- ronments. Conclusion. — 1. What are the factors in the environment of living things ? 2. Tabulate the factors as suggested below : Plant ^Tviirval I^ctru Factors of Environment JPi^ohleni 2 : Compwidson of a natural with an artificial en- viromnent. Method and Observations. — Determine what is added to or subtracted from your home environment to make it different from the natural environment of the country. Make two columns. In the first, place the factors of a natural environment. In the second, place the factors of the environment in a city or town. TS atixrctl Qi^ti^ici al Remember that the city has various agencies which add to the air certain substances ; that housing conditions are changed ; that the earth is covered by pavement ; and that water supplies and disposal of waste through sewers are artificial factors. Think, too, of many other ways in which the city environment is changed. % C. suite ColUge PROBLEM 3 25 Put down all the artificial things that havo boon nMvd to or sub- tracted from your home environment lo in.ikr a dilTurenl from a natural environment. Conclusion. — In what respects does a city ciivironincnt difTcr from that of the country? Problem 3 : To test my home eiivironnLciit. Method and Observations. — Usin^- tlu* hnns(» score card pivcn below, estimate the condition of your home environment . This is an exercise for your own use and need not he shown in dans unless you so desire. When in doubt consult your teacher. House Score Card Rooms Light 10, gloomy 5, dark ... Well ventilated 1.5, poorly 7, badly Repair : good 5, fair 3, poor 1, bad Clean 10, soiled 5, dirty 2, filthy . I 11 III IV V VI VII VIII — 1 i! ""lo 15 5 10" 5 3 One person to room 10, 2 to room 8, 3 to room 4, 4 or more . 10 Sinks j Construction : good 5, fair 2, bad 1 Water-closet I Construction: good 3, fair 2, poor 1, bad Condition: clean 3, dirty 1, filthy 3 1 compartment for 1 family 3, for 2 families 1, for more than i 2 families • -^ Cleanliness 1 bath tub for 1 apartment 3, for more than 1 apartnuiil 1. ii<. bath -^ Personal cleanhness : very clean 7, fairly cU'an .'>, dirty 2. lihliy i 7 Washing Stationary tubs 3, removable 2, no tubs -^ Cleanhness of clothing : very clean 7, fairly clean .">, dirty "J. liithy O ' 7 Meals Regular 4, irregular 2, uncertain * Amount and kind of food : good 4, fair 2. poor I. I'a.l n . Cooking: very clean 4, clean 3, dirty 1, fiUliy Refrigeration : good 4, fair 2, poor 1, non(> 4 \ 1 1(NI 26 ENVIRONMENT OF PLANTS AND ANIMALS Definitions of Terms used in House Score Card^ Rooms : Light — Light enough to read easily in every part. (In estimat- ing the light, ventilation, and repair of an apartment, di\ide the sum of the scores of all the rooms by the number of rooms.) Gloomy — Not light enough to read easily in every part, but enough to see one's way about readily when doors are closed. Dark — Too dark to see one's way about easily when doors are closed. Well Ventilated — With window on street or fair-sized 3'ard. Poorly Ventilated — With ^dndow opening on a shallow yard or on a narrow court, open to the sky at the top, or else with 5x3 inside window (15 square feet) opening on a well-ventilated room in same apartment. Badly Ventilated — With no window on the street, or on a yard, or on a court open to the sky, and Math no window, or a very small window, opening on an adjoining room. In Good Repair — No torn wall paper, broken plaster, broken woodwork or flooring, nor badly shrunk or warped floor boards or wainscoting, lea\ang large cracks. In Fair Repair — Slightly torn or loose wall paper, shghtly broken plaster, warped floor boards and wainscoting. In Bad Repair — Very badly torn wall paper or broken plaster over a considerable area, or badly broken woodwork or flooring. (Rooms not exactly coinciding \\dth any of the three classes are to be included in the one the description of which comes nearest to the condition.) Sinks : Good — Iron, on iron supports mth iron back above to prevent splashing of water on wall surface, in light location, used for one family. Water direct from city water mains or from a clean roof tank. Bad — Surrounded by wood rims with or mthout metal flushings, space beneath inclosed Tvdth wood risers ; dark location, used by more than one family ; water from dirty roof tank. Fair — Midway between above two extremes. Water-closet: Good — Indoor closet. In well-lighted and ventilated location, closet fixture entirely open underneath, abundant water flush. Fair — Indoor closet, poor condition — badly lighted and ventilated location, fixture inclosed with wood risers, or poor flush. Poor — Yard closet — separate water-closet in indi\adual compartment in the yard. Bad — School sink — sewer-connected privy, having one continuous vault beneath the row of indi\ddual toilet compartments. Conclusion. — 1 . Is my home environment as good as it should be ? 2. How might I improve it ? 1 This and the following are modified from Allen, Civics and Health, Ginn and Company. PROBLEiM 4 27 Problem 4: To Team fJir ronditions of nnj cil ij rnriinniiLt iil. Method and Observations. — Uso this scoic c.iid in m manner similar to that of your last exercise. .Iii(l^<' cnch item carcfullv. Score Card tor Citizens' Use Schoolhouse: Well ventilated, 20; badly, 0-10 . . Cleaned regularly, 20 ; irregularly, 0-10 . . Feather duster prohibited, no dry sweeping, 10 Bubble fountains, 10 Has adequate play space, 10; inadequate, 0-.") Has clean drinking water, 10 Has clean toilets, 10 ; unclean, 0-5 .... Outdoor recreation parks, 10 ; none, . . . Church : Well ventilated, 10 ; badly, 0-5 . . Heat evenly distributed, 10 ; unevenly, 0-5 Cleaned regularly, 10 ; irregularly, 0-5 . . Without carpets, 10 Without plush seats, 10 Streets: Sewerage underground, 20; surface, 0-10 No pools neglected, 10 No -garbage piled up, 10 Swept regularly, 20 ; irregularly, 0-10 .... Sprinkled and flushed, 10 Has baskets for refuse, 10 All districts equally cleaned, 20 ; unequally, 0-10 Near-hy Stores: Clean, 10; poorly cleaned, 0-5 Free from flies, 10 ; partly, 0-5 . . . . Food screened, 10 ; partly, 0-5 . . . . Milk used in bottles, 10 ; dipped, . . Grade goods high, 10 ; medium, 5-0 . . Home: Use score card already worked out Multiply total by 2, making perfect total Grand total i k. i\r r.i i 20 20 10 10 10 10 10 10 100 10 10 10 10 10 50 20 10 10 20 10 10 _20_ 100 10 10 10 10 10 50 2U) .500 ALL...V Conclusion. — Allowino- 200 as l)acl, 250 as poor. :m pas.^alde, 350 fair, 400 good, 450 and above exceUent. estimate tlie ccndi- tions of your environment. 28 ENVIRONMENT OF PLANTS AND ANIMALS Problem 5 : To determine and to illustrate hy a graph the changes of temperature {one of the factoids of the environmejit) during a given day. Materials. — Thermometer, clock, graph paper. Method and Observations. — Take the temperature (outside) at 7 A.M. and at each successive hour during the day until 6 p.m. On a piece of graph paper lay off a line parallel to the bottom of the page. On this line, at equal distances, place your hours, beginning at 7 and ending at 6. Then from the line made as a base, erect perpendiculars on each of the hour marks. On these perpendiculars mark the record of the thermometer at the given hour. Begin your record at the base line, e.g., if the thermometer IXQ h 50^ z — = 45 40- - ^ = 3S 30^ = - = 25 20- E ^ -15_ — f: - IIIIMI E 5 o;E ©a 1 m m^im so 40 30 20 _ 10 o I— I (51 45 33 -ZS -15 ^ n (£iji[i] ^ so 40 30 zo lo 45 -35 - q 2$ 15 SO 40 30 20 Hi 10 45 35 -25 IS m PROBLEM 5 29 registers 50° at 7 a.m., make 50 your start- ing point on the line, and if the thennoino- ter has risen to 56° at 8 o'clock, then count off six squares on your graph paper ai)ove the base line. Do this for each hour in the 12 for which your record has been made. Connect the marks made on the vertical lines. The result is a curve like the accompanying, showing the tempera- ture record of the day. Conclusion. — What changes take place in the temperature factor of a given day? NOTE. — Another suggested exercise is: Relation of the body to intake of water. n IT 14 ty n n ;i : '■I: (9Metwcen plants and animals. 2. To learn. to know a few common insects, and to collect them for later study. 3. To have such an enjoyable time that you will wish to go again by yourself. a. Insects and Flowers Method and Observations. — Your trip should include fields and waste lots, covered with weeds and trees. Look for six-legged animals (insects) on plants. Do they receive any jirotection from such plants? Shelter? Food? CJive exami)les under each of th'e above headings. Do you find any insects laying their eggs upon plants? Why do you think they do this? Follow a bee until it alights on a flower. Try to hnd out exactly what it gets from the flower, and how it does it. Now observe where it goes next. Do bees visit flowers of the same kind in succession ? What are your conclusions regarding the nuitual relations Ik?- tween the bee and the flower? Do both receive benefit? Write your answer on paper supplied by your instructor. Look for other flying insects that are on flowers. Extra credit is given for the working out of the relation between a buttertl\- and a flower. Carefully observe the goldenrod blossoms tor \ellow and black beetles (locust borer) about 1 inch long. Does the be(>tle get any good from the plant? Might it give the plant aiiythiiig in return? Write a paragraph on this. Observe grasshoppers or other insects on stalks of gra. /) 1 1, ra, straight wings). — Found on most green weeds. The mouth parts are fitted fnv biting. Hind wings, if present, are foldcMl uj) lengthwise undiM- the outer wings when at rest. FHes (/)/>/r/v/, two wings). — Usually small insects with but a single i)air of gauzy wings. A short ):)r()boscis. Bugs {Uciniptcra, half wings).— The wings 30 INTERRELATIONS OF PLANTS AND ANIMALS are not alone sufficient identification, as they may or may not be present. A jointed pro- boscis which points backwards is the only sure means of knowing this group. Beetles (Coleoptera, sheath wings). — Characterized by having a strong front pair of wings called elytra, usually covering the hind wings and always meeting in a straight line down the middle of the back. Mouth parts hard, pincher-like jaws. a. Field Work Method. — Collect as many different kinds of insects as you can, making careful notes as to the locality where the insect was found, the flowers which it frequents, the kind of food it was tak- ing from the flower, and the order to which it belongs. b. Laboratory Work Observations. — From boxes containing a number of different insects pick out one from each order given above and give your reasons for placing that particular insect in the order which you have chosen for it. Conclusion. — 1. Why do certain insects always frequent certain flowers? Look at the insect, especially the mouth parts, ver3^ carefully and study the form of the flower before making your decision. 2. How would you pick out (a) a bee, (6) a butterfly, (c) a bug, (d) a grasshopper from the above insects? Problem 11 an insect. To study the life history {jnetamorphosis) of Note. — Field work may be done at a museum, or questions may be worked out from some of the excellent preparations made by the Kny-Scheerer Company or other of the biological supply houses. PR01U.EM 11 ;i7 a. Eggs Method and Observations. — In the field look on the inidcr side of leaves for tiny ovoid structures {('(jy.s) of mot hs Mrid hiitlerfiies. The eggs of the cabbage butterfly may be found at almost any time on the under side of cabbage leaves. Conclusion. — Why are the eggs laid on the //.////tr side of certain leaves? b. Larva or Caterpillar Observatipns. — Note that, besides true jointed logs, tlu^ caterpillar has others called prolegs. Ht)\v many true legs ar(» there and where are they located? How many prologs are there? Locate the spiracles or breathing holes. Remember wlicre they are located on an adult insect. Watch the caterpillar when it feeds. AVhat kind of mouth parts does it have? Might it do damage to plants? How".' Conclusion. — 1. Is a caterpillar a worm? (Look in your bi- ology for the characteristics of worms.) 2. How might the larvae of moths or butterflies l)e of economic importance ? c. Pupa Materials. — Cocoons of several species of moths with twigs or other parts attached should be furnished for this exercise. Note. — Moths spin a cocoon for themselves at this stage. Huttcrflics spin no cocoon but form a chrysalis. Observations. — Where do you find the cocoon or chry.salis? Of what does the cocoon seem to be compo.sed? (Tlie cocoon of the Cecropia is excellent for this purpose.) In a chrysalis locate by means of the body markings the head, antennae or feelers, eyes, wings, legs, and spiracles. Are all the parts of an adult present? Open a cocoon. What do you find insid(^'.' Hnw do you explain this? Conclusion. — Making use of all the knowledge you have gained, write a brief description of the i)ui)al stage of an in.sect and tell of what use this stage might be to the insect. KcMiiember where you find these stages. 38 INTERRELATIONS OF PLANTS AND ANIMALS d. Adult or Imago Method. — Examine carefully an adult Initterfly or moth. Observations. — How many body regions has it? How many legs ? Wings ? Antennae ? How does this stage differ from the pupal stage? Note. — All the changes undergone by an animal from the time it leaves the egg to the time it becomes an adult are known as the stages of metamorphosis of that animal. If no great changes in form occur, then the animal is said to have an incomplete or direct metamorphosis. But if changes in form such as we have just seen occur, then the animal is said to pass through a complete or indirect metamorphosis. Conclusion. — 1. What insects that you have studied pass through a direct metamorphosis? An indirect metamorphosis? 2. If time permits, drawings might be made to illustrate the life history (metamorphosis) of a moth or a butterfly. Problem 12: To learn the structure and worh of the parts of a flower. Materials. — Any large flower, as the tulip in the spring, or eve- ning primrose or gladiolus in the fall. Method. — Carefully examine the parts of a flower. Note. — Flowers are built so that the parts are arranged in circles. In regular flowers the same number of parts (or multiples of these parts) will be found in each circle. Observations.^ — How many parts in the outermost circle? These parts are called sepals. Collectively they make up the calyx. What color have the sepals? In a young flower what seems to be their use ? The next circle of parts is called the petals. How many are there? What color do they have? Together they form the corolla. The little knobbed organs are called stamens; the stalk is the filament, the knob the anther. Describe what you find in the anthers. This is the pollen. Can you determine how it gets out of the anthers? Use a hand lens. In the center of the flower is the pistil.^ Describe it. The 1 If the pistil is made up of a number of separate parts, each part is called a carpel. PROBLEM 13 39 Part Gf Color Slicipe Use. Petal Sepal Starrven Pistil enlarged part at the base (not always easily seen; is the uvanj; the stalk is the style; the tip, which is sticky, is called the Hlif^mn. On this sticky surface pollen grains will grow. IIow \\<\si\\\ pollen get to the stigma? Cut a cross section through the ovanj. Describe what you find inside. These little structures are called ovules. Under cer- tain conditions, which we will later discuss, a part of a pollen grain will cause these ovules to grow into seeds. Fill out a diagram like the accompany- ing in yoiir notebook. Conclusion. — 1. What parts of the flower are essential for tlic production of seeds? 2. What are then the essential organs of a flower? Drawings. — 1. A flower from above. Label all parts. 2. A stamen, showing all parts. 3. A pistil, showing all parts. Problem 13: The cross-pollination of Jhnrrrs. Method. — Take a trip to a locality wlicrc flowers are a])uri(iant and make a preliminary study of the relation of in.^ccts to flowers. Observations. — Notice whether the flowers are being visited by insects. To what orders do these insects belong? Do bees visit flowers of one sort in succession, or of dilTerent sorts? Make a careful study of this point by following a .single bee or other insect. AVork this out in tlie case of a butterfly. Do insects seem to prefer any one color in flowers to another color? Make careful o])servations on this i)oini. Can you discover any means by which the flower iniiiht affraef an insect? Remember insects can probably smell and taste a.s 40 INTERRELATIONS OF PLANTS AND ANIMALS well as see. Might the shape of a flower be of use to an insect? How? Conclusion. — L What do insects get from flowers? 2. What kinds of flowers do they frequent most? 3. What do insects give to flowers? ' Problem 14: To study cross-pollination in butter and eg^s. Note. — in the fall of the year one of the best flowers for study is found in the yellow butter and eggs {Linaria vulgaris) found in vacant lots and along roadsides. Any cultivated forms of the toadflax family are useful for this purpose. Materials. — Butter and eggs or other member of the toadflax family, bumblebees in formalin, needle, hand lens. (Diagrams, p. 39, Civic Biology.) Method. — Study carefully the structure of butter and eggs for any adaptations or fitness in structure : (1) to receive insect visitors ; (2) to effect self- or cross-pollination. Observations. — Note the shape of the flower. Are all its petals and sepals regular (the same size and shape) ? Might the shape of the flower offer any place for an insect (as a bee) to light? Try it with a bee. What would happen when the body of the bee rested on the lower lip of the flower ? Press down this lower lip and look inside the flower for the stamens and pistil. What is there peculiar about the position of the stamens ? Hold the flower in a natural position. Could pollen from the stamens reach the pistil? Examine with hand lens the sides, back, legs, and head of a bumblebee. What do you find? Now push the body of the bee into an open flower. (Remember that the nectar the bee seeks is held in the spur, or pointed projection, of the flower.) Over what structures would the head and back of the bee rub? If the bee visited another flower of the same sort, what would happen ? Conclusion. — 1. How is the butter and eggs fitted to receive insect visitors? 2. What kind of pollination is most common in butter and eggs? How is it brought about? 3. Explain a second method of pollination in butter and eggs. PROBLEM 15 11 4. Make a drawing (diagram) to show liow a bee liclps to pollinate butter and eggs. Prohlem 15 : Special directions for the study of some fall flowers. (Extra.) i The Evening Primrose (Onagra bienriis). — The liabitat pre- ferred by this flower is dry fields, roadsides, or waste places. The yellow flowers are found in long, upright, densely crowded chisters. A flower cluster in which the indivickial flowers have no flower stalks or pedicles, with one main axis to the cluster, is called a sjyike. Notice that young and old flowers and fruits are all on the same cluster. Where are the youngest flowers located in llic cluster? Is there any flower at the end of the main stalk ? Could you deter- mine in advance the length of the flower cluster? Such a cluster is said to be indeterminate. Why? Study a single open flower. Note the^calyx and corolla. Are the parts distinct? How many petals do you find? Notice that there are eight stamens and that the stigma is four-parted. Cut the ovary in cross section, and see how many locules (spaces) there are. When a flower has each circle of parts, as the sepals, petals, stamens, and pistils, made up of a certain number of divisions, or when they appear in multiples of that number, the flower is said to be symmetrical. Here we see a very striking example of sym- metry in a flower. The chief attraction to insects is the nectar, which is formed in nectar glands at the base inside the slender tubular corolla. In- formation is given to the insects of the contents by a faint, sweet odor. This flower is not visited by many day-flying in.^^cts. Can you determine the names of any that do come by day? At night the flower opens more widely and the scent becomes much iTo THE Teacher. — If the work on flowers is taken up in (he sprint:, field work should result in the collection of jack-in-the-pulpit, oak. wilh)w. skunk cahhaKo. grasses, and also many wild flowers which show special achiptations for cross-polli- nation. In the fall butterfly weed, Salvia, turtlehead. and various comi>ositC8 show wonderful adaptation. Original investigation on simple i)rohloms of thi.** kind have been found by the writer to he the best means of stimul.ating certain better prepared students to take an abiding interest in this work. Two or thrcr sample investigations are given here that might be used by the student Jis a form in jnaking reports on other flowers. 42 INTERRELATIONS OF PLANTS AND ANIMALS more noticeable. Moths are its chief night visitors. The long proboscis is thrust into the flower and quickly withdrawn, but usuall}^ a little pollen is carried off on the palps (projections on the sides of the head). This may be left on the next flower visited. Try to determine what other insects, if any, visit the evening primrose at night. Draw a single flower split open lengthwise to show the position of the parts, and especially any adaptations to insect pollination. Look for any special means for the prevention of self-pollination. Label all the parts. Moth Mullein {Verhascum blattaria). — The moth mullein is one of the most beautiful weeds, despite the fact that few blos- soms are found at any given time. The plant flourishes on dry, waste land, roadsides, and open fields. It w-as introduced into this country and has since become common here and in Canada. The flowers are found in a long, loose raceme. A raceme is like a spike, except that each flower has its own flower stalk devel- oped. Has this cluster yellow or white flowers ? Into how many parts is the calyx divided ? The corolla ? Is the corolla perfectly regular? Notice the five stamens. Is there anything peculiar about the filaments ? Are they all of the same length ? In spite of the fact that the flower is called moth mullein, it is not polli- nated to any extent by moths. Bees and flies are the chief pollen bearers. Bees which alight on this flower do so for the purpose of collecting pollen. This they usually gather from the short stamens, while they cling to the longer ones. As the bee lights on another flower, the pollen on the under side of the body is trans- ferred to the stigma of this flower. Draw the flower from above, twice natural size. Jewelweed {Impatiens hiflora). — One of the most prevalent of all our brookside flowers is the jewelweed. It well deserves its name, a pendant flaming jewel of orange. This flower is very irregular in shape. Are the flowers single or in clusters? The sepals as well as the petals are colored. The former are three in number, one of which is sacklike in shape and contracted at one end into a spur. The petals are also three in number. Open the flower. Notice how short the filaments of PROBLEM H> l:i the five stamens are. Make a note of Ihcir position with relation to the pistil. Would self-pollination he possible in tiiis (lower? If it is possible to study jewelweed out of doors in its native habitat, it will be found that hunnnin^- birds are tlie visitors which seem best adapted to cross-pollinate the flower. A care- ful series of observations by some girl or boy upon the cross- pollination of this flower might add much to our knowledge regarding it. Jewelweed has the habit of producing (usually in the fall) inconspicuous flowers which never open but which produce .seeds capable of germination and growth. vSuch flowers are said to be cleistogamous. In England, where the plant has been introduced, it is found to produce more cleistogamous flowers than showy ones, and the showy ones do not produce seed. There are no humming birds in /England, and without this means of pollination, the cleistogamous form prevails. Make a front-view drawing of the flower of jewelweed twice natural size. Proble^n 16: To find other poUinating agents besides inserts. Materials and Method. — Study as many other llowers as possible, using Kny or other charts and books of reference to help in your work. Suggested for this are various types of orchids (described and pictured by Charles Darwin), turtlehead, Sulria, and others previously mentioned. Observations. — Look for any peculiarities of structure that seem to be for purposes of pollination. Explain. If j)ossible, study especially the structure of the flowers of sagi\ pea or bean, and butterfly weed. Find out how pol- lination is accom- plished in the corn plant ; in the pines and grasses. Read- ing as well as field work wdll help here. Are stamens and pis- Polliivatibrv. E^TCCVTXVpleS iTx^ects ^v>^iiva Vv^cit ei' OtKer Adeixt^ 44 INTERRELATIONS OF PLANTS AND ANIMALS tils ever separated by being on different plants? Give examples. ExpLain. Conclusion. — Using a form like that on page 43, tabulate the various ways in which pollination is brought about. Problem Questions 1. What relation might insects and plants have to each other? Is this relation always a useful one? 2. How could you tell an insect from other animals? 3. How could you tell a bee, butterfly, bug, grasshopper, beetle? 4. What is meant by metamorphosis? 5. Of what use might metamorphosis be to an insect? 6. Which is the most beneficial stage of the metamorphosis of a moth or a butterfly? The most harmful stage? Why? 7. Of what use to a flower are its sepals, petals, stamens, pistil? 8. What parts could a flower do without? Why? 9. What do insects get from flowers? What do they do with what they get ? 10. Is pollination intended by an insect? 11. What do we mean by an adaptation f Illustrate from a flower. 12. What do we mean by a wiiiitaZ adaptation ? Illustrate from a flower and an insect. 13. What adaptations are found in flowers to prevent self- pollination? Give examples. 14. What agents other than insects might transfer pollen? 15. Compare with your own environment the environment which you have found animals and plants to have in the park. How are the two environments alike and how do they differ? 16. What constitutes an artificial environment? A natural environment ? 17. What are some uses to you of a city park? Do not look in your book for an answer. Reference Books Hunter, Civic Biology, Chap. III. American Book Company, Hunter, Elements of Biology , Chap. IV. American Book Company. Hunter, Essentials of Biology, Chap. IV. American Book Company. Andrews, Botany All the Year Round, pp. 222-236. American Book Company. REFERENCE BOOKS 15 Atkinson, First Studies of Plant Life, Chaps. XXV-XXVI. Ciiun .-md rorni>!iny. Bailey, Crossing of Egg Plants, Bulletin 26, Cornell Exi)orinjcnt SUition. Bailey, Effect of Pollination upon Tomatoes, Bulletin 2S, ( 'ornoll Kxperinient Sta- tion. Bailey, Philosophy of Crossing Plants, Considered in liifcrcncc to thrir Imjtrorement under Cultivation. Report of Massachusetts State Board <»f A«rirulturo. ls'j\. Bailey, New Ideals in the Improvement of Plants. Country Life in America, July, 1903. Bailey, Plant Breeding. The Macmillan Company. Bergen and Caldwell, Practical Botany, Chap. VIII. Ginn an«i Conipany. Campbell, Lectures on the Evolution of Plants. The Macniilhin Company. Coulter, Plant Life and Plant Uses, pp. 301-322. American liook Cfjm|»:iriy. Coulter, Plant Studies, Chap. VII. D. Appleton and Company. Coulter, Barnes, and Cowles, A Textbook of Botany, Part II. .\mcriran Book Company. Crosby, School Exercises in Plant Production, Farmers' Bulletin 408, U. S. Depart- ment of Agriculture. Crosby and Howe, School Lessons on Corn, Farmers' Bulletin 409, U. S. Depart- ment of Agriculture. Dana, How to Know the Wild Flowers. Scribner's Sons. Dana, Plants and Their Children, pp. 187-255. American Book Company. Darwin, Insectivorous Plants. D. Appleton and Company. Darwin, Different Forms of Flowers on Plants of the Same Species. I), .\ppleton and Company. Darwin, Fertilization in the Vegetable Kingdom, Chaps. I and II. D. Appleton and Company. Darwin, Orchids Fertilized by Insects. D. Appleton and Company. Darwin, Cross and Self Fertilization in the Vegetable Kingdom. 1). .\ppleton and Company. De Vries, Plant Breeding. Paul, Kegan, Trench, Trubncr and Company. London. East, The Rdle of Selection in Plant Breeding. Popular Science Monthly, Aujfust, 1910. Ely, Color Arrangement of Flowers. Scribner's Magazine, March. ISHO. Gibson, My Studio Neighbors, p. 227. Harper and Brothers. Henderson, Functions of an Environment. Science, April 10, r.>14. Howe, How to Test Seed Corn in School. Circular 96, U. S. Departn.ont of Auri- culture. lies, Teachiyig Farmers' Children on the Ground. World's Work, .M:i> . 1«K«. Lubbock, British Wild Flowers. The Macmillan ( ompany. Lubbock, Flowers, Fruits, and Leaves, Part I. The Macmillan Company. Lyle, Plant Breeding in a Dutch Garden. Everybody's Magazine, .Tunc. 1902. Miiller, The Fertilization of Flowers. The Macmillan Company. Needham, General Biology, pp. 1-50. The Comstock Publishing Company. Newell, A Reader in Botany, Part II. pp. 1-90. Ginn and Company. Osterhout, Experiments ivith Plants, Chap. VI. The Macmillan Company. Parsons, Children's Gardens for Pleasure, Health, and Education, bturpis and Walton. Sharpe, A Laboratory Manual in Biology. Ameri.-an B.M.k Company. Stack, Wild Flowers Every Child Should Know. Doublcday. Page and C ompan> . IV. THE FUNCTIONS AND COMPOSITION OF LIVING THINGS Problems. — To discover the functions of living matter. (a) In a living plant. (,b) In a living animal. Laboratory Suggestions Laboratory study of a living plant. — Any whole plant may be used ; a weed is preferable. Laboratory demonstration or home study. — The functions of a living animal. Demonstration. — The growth of pollen tubes. Laboratory exercise. — The growth of the mature ovary into the fruit, e.g., bean or pea pod. To THE Teacher. — The object of this chapter is first to give the child a pre- liminary or pre-view of the larger problem outlined in the six following chapters, i.e., plant growth and nutrition. Then the concept of the cell as a unit of structure should be worked out and the very important notion of fertilization in its relation to the development of the plant. Problems 17, 18, 19, and 20 might well follow Chapter II, if the teacher desires, and the problems on fertilization introduced after that of the structure of the flower. Experience has shown the sequence here followed, however, to work out well. Any simple plant or animal tissue can be used to demonstrate the cell. Epider- mal cells may be stripped from the body of the frog or obtained by scraping the inside of one's mouth. The thin skin from an onion stained with tincture of iodine shows well, as do thin cross sections of a young stem, as the bean or pea. One of the best places to study a tissue and the cells of which it is composed is in the leaf of a green water plant, Elodea. In this plant the cells are large, and not only their out- line, but the movement of the living matter within the cells, may easily be seen, and the parts described in the next problem can be demonstrated. Problem 1 7 : The uses of the parts of a plant. Materials. — Growing plants, seedlings, and red ink. NOTE. — A growing plant has roots, stems, leaves, flowers, and fruits. Method and Observations. — Locate each part in the specimen before you. If you water a growing plant that is badly wilted, 4G PUOBLEAl 18 47 what happens? What would one use of llic roots he? W liat holds a plant iii the ground? In seedhn^s the roots of whifli have been placed in red ink note carefully the appearance of root, stem, and leaves. Note that the rod fluid extends into the leaves. How did it get there? What is one use of the stem to (he plant? Examine a piece of sugar cane, a stem. Taste it. What does it contain? What might another use of stems he? Examine leaves which are in a sunny window. How arc (hey placed with reference to the light? Later we will find tha( green leaves make food for the plant when in the sunligiit. We have seen flowers, and found that in time they form fruits. Fruits in turn hold the seeds which give rise to new plants. Conclusion. — 1. Write a short compo- sition on the uses of all of its parts to a green plant. 2. Fill in a table hke the accompanying. Problem IS: To study the needs and use.^ of fhr jinrf'^ of a living animal. Method. — Study your pet cat or dog. Make a list of all (he things that your pet requires in order to live. Classify tlu^ intake of the pet under the headings, Food, Water, Air, etc. What parts of the body have to do with taking in food ".' Water? Air? When a structure has a work to do, we call (ha( work its function. What other functions has your pet besiik\s tho«' ahi-ady mentioned? (Your teacher will helj:) you here.) Conclusion. — What are the needs and what arc th(» functions of a living animal? How do you think they compare wi(h those of a plant? STUDY OF COMPOUXD MirilOSCOPE 1. NOTE. — The microscope, an instrument for makinn .•^n.all ohjort,s ai.i>oar larger, comprises two parts: the stand (A. B. C) anec- tively show? What is the use of the mirrors? 7. NOTE. — A hollow cylinder containing two lenses fits into the upper end of the tube. It is called the eyepiece or ocular. (G). Why is the name eyepiece applied? 8. NOTE. — Small brass mounts, each containing several lenses, are attached to the tube at its lower end; they are the object lenses or objectives (F, F). Why is the name objective given to these lenses? How many objective.s arc there in your microscope? 9. NOTE. — The low power (a slightly magnifying objective) has a .short and broad mount. The high-power objective has a long and narrow mount. What fractional numbers do you find on the mount of the high anlasm) containing a portion which in part readily absorbs stain. This structure ia called the nucleus. A cell is usually bounded by a cell wall or ccJl membrane. HUNTER LAB. PROS. — 4 50 FUNCTIONS OF LIVING THINGS Diagram Showing Cells. N, nucleus ; P, protoplasm ; W, walls. Observations. — What is the shape of a single cell? Are all cells examined the same size? Shape? Can you lo- cate the nucleus (a deeply stained body) , cytoplasm (pro- toplasm outside the nucleus), and cell wall? Any other structures ? Are the cells separate or united with one another? Note. — Cells of the same sort joined together in a plant or an animal form tissues. Tissues are grouped in both plants and animals to form organs, struc- tures which have some certain work to do, as a leaf, a root, a hand, an eye, etc. Conclusion. — 1. In the onion do the cells form tissues? Give reason for your answer. 2. What are tissues ? Of what are tissues composed ? 3. What are organs? Give examples from your own body. 4. Define a cell from what you have seen under the microscope. 5. (Optional.) Draw a few of the cells stained with methyl blue or iodine, showing cell walls, nuclei, and protoplasm. Pi^obletn 20 : To determiiie some of the properties of proto- plasm. Materials. — Stamen hairs of spiderwort {Tradescantia) , leaves of Elodea, or the root hairs of radish or grain seedlings are useful. As Elodea is easily grown in aquaria, it is recommended for this exercise. Observations. — Examine a bit of mounted leaf of Elodea. What is its general appearance under the low power? Can you locate individual cells in the mass ? Note the green bodies in the cells {chlorophyll bodies) . Can you find the cell walls ? The liv- ing matter (protoplasm) ? Look closely along the edge of the cells for any movement of living matter within the cell. Does the protoplasm move in any particular direction? PUUBLE.M 22 51 Heat the slide very slightly. Wliat is llic rcsuh ? (ool tlic slide and note the effect on cell movenieiil. Conclusion. — 1. In what part of planls may j)n)t()pla>ni Ik; found ? 2. Write a paragraph, descri})in<2; tlic :ii)|)('aiaii('c. niovcnicnt, and composition of protoplasm in Elodcu. \\ hat arc its rcdduniH (look up this word in the dictionary) to heat and cold? Problem 21 : To study structure and groivth oj' iJoUcn. Materials. — Pollen of snapdragon, sweet i)ea, nit-^turtium, or tulip; sugar solution (3 per cent, 10 per cent, and 1') per cent), bell jar, sponge, a compound microscope, hand lens. Method. — ^Dust some pollen of snaptlragon on a glass sHde. Examine it with a hand lens. Make a 10 per cent sohition of cano sugar and dust some ripe pollen in a drop of the solution placed on a glass slide. Place this slide under a small Itcll jai- with a moist sponge and examine after 24 hours with the low j)owcr of the compound microscope. Try sweet pea or nasturtium pollen in a 15 per cent sugar solution, or tulip with a '-^ i)er cent su^ar solution. Observations. — Look for a tubelike structure, the pr in the soil? 22. What kinds of soil retard evaporation? Why? 23. Why do we hear so much nowadays of going back to the soil ? What does this term mean ? HUNTER LAB. PROB. — G 82 SOIL AND ITS RELATION TO ROOTS Reference Books Hunter, Civic Biology, Chap. VI. American Book Company. Hunter, Elements of Biology, Chap. VII. American Book Company. Hunter, Essentials of Biology, Chap. VII. American Book Company. Andrews, Botany All the Year Round, Chap. II. American Book Company. Atkinson, First Studies of Plant Life, Chaps. IX, XI, XII. Ginn and Company.. Bailey, Principles of Agriculture, Chaps. V, VI. The Macmillan Company. Bailey, The Rotation of Crops. Cosmopolitan Magazine, April, 1905. Baldwin, The Human Side of Farming. The Outlook, Aug. 27, 1910. Briggs and others. The Centrifugal Method of Soil Analysis. Bulletin No. 24, Bureau of Soils, U. S. Department of Agriculture, 1904. Burkett, The Vital Facts of Agriculture. Country Life in A^nerica, January, 1905. Burkett, What Crops to Grow and How to Put the Land in Condition. Country Life in America. January, 1905. Clinton, Soil, What it Does. Carnell University Nature Study Quarterly, No. 2, October, 1909. Clute, Agronomy. Ginn and Company. Coulter, Plant Life and Plant Uses, Chaps. Ill, IV. American Book Company. Coulter, Barnes, and Cowles, A Textbook of Botany, Part II. American Book Company. Detmer-Moor, Practical Plant Physiology. The Macmillan Company. Duggar, Plant Physiology. The Macmillan Company. Fairchild, The New Hope of Farmers. World's Work, July, 1906. Field, Scientific Agriculture. Report of the Rhode Island Board of Agriculture, 1896. Fippin, The Soil, Its Use and Abuse. Cornell Reading Course Bulletin, Oct. 15, 1911. Goflf and Mayne, First Principles of Agriculture. American Book Company. Goodale, Physiological Botany. American Book Company. Gray, Structural Botany, pp. 27-39, 56-64. American Book Company. Green, Vegetable Physiology, Chaps. V, VI. J. and A. Churchill. Hall, The Soil as a Battle Ground. Harpers' Magazine, October, 1910. Hilgard, Soils, their Formation. The Macmillan Company. Hunt, The Importance of Nitrogen in the Growth of Plants. Cornell University Experiment Station Bulletin, No. 247, June, 1907. Huntington, Beans and Peas for Fertilizer. Long Island Agronomist, No. 8, Nov. 3, 1909. Jenkins, Keeping up Fertility. Garden Magazine — Farming, June, 1910. Kerner-Oliver, Natural History of Plants. Henry Holt and Company. MacDougal, Plant Physiology. Longmans, Green and Company. Martin, The Work of the Brook. Cornell University Nature Study Quarterly, No. 5, June, 1900. Massey, Practical Farming. A. C. McClurg and Company. Moore, The Physiology of Man and Other Animals. Henry Holt and Company. Moore, Soil Inoculation. Century Magazine, October, 1904. Murray, Soils and Manures. D. Van Nostrand and Company. Pfeffer, The Physiology of Plants. Clarendon Press. Seton, Gophers as Soil Formers. Century Magazine, June, 1904. IIEFEKENCE BOOKS 83 Stevens, Introduction to Botany, pp. ;dl-44. D. ('. Heath and CoinpiuiN . Tarr, .1 Handful of Soil. Cornell University Nature Study Quarterly, \o. 2, (Octo- ber, 1899. Tarr, A Summer Shower. Cornell University Bulletin No. 1, .lunc, 1S99. Warren, Elements of Agriculture. The Macniillan ('onipany. Wilkinson, Practical Agriculture. American Book Company. VII. PLANT GROWTH AND NUTRITION — PLANTS MAKE FOOD Problem. — Wlwre, when, and how green plants make food. {a) How and why is inoisture given off from leaves? (b) What is the reaction of leaves to light ? (c) What is made in green leaves in the sunlight ? id) What by-prodiiets are given off in the above process ? (e) Other functions of leaves. Laboratory Suggestions Dernonstration. — Water given off by plant in sunlight. Loss of weight due to transpiration measured. Laboratory exercise. — (a) Gross structure of a leaf. (6) Study of stoma and lower epidermis under microscope. (c) Study of cross section to show cells and air spaces. Demonstration. — Reaction of leaves to light. Demonstration. — Light necessary to starch making. Demonstration. — Air necessary to starch making. Demonstration. — Oxygen a by-product of starch making. To THE Teacher. — In this chapter experimental work may be made to carry- almost the entire plan of the chapter. That plants make food out of raw food materials may be demonstrated by a series of logical experiments which leave no doubt as to the steps taken or the factors involved in this wonderful process. That the whole world depends upon the process of photosynthesis is well known. A concept of what the process is and what it does for mankind should be known by every pupil when he has finished the exercises which follow. Laboratory problems having rigid adherence to the logical sequence of events which culminate in food making and food storage in the leaf, will result in increased power on the part of the pupil and a beginning of appreciation of what a developed problem really means. To the critic who would object to so much time given to the processes involved in photosynthesis we would say : starch making and food making may be tied up in a vital manner to the interest of the city child by drawing atten- tion to the economic importance of cereal and other staples furnished man by plants, and by making clear the tremendous importance of green plants in the role of food makers on the earth. (See Chapter XI, Civic Biology.) 84 PROBLEM ()7 85 Prohleni 65 : To prove that water is <^ivpn off hy a ^rccn ])Iant. Materials. — Bell jar, a j;rowin«;- sinji;le-stcmmc(l ^rcon i)lant as a geranium, rul)l)or tissue, l)alance. Method 1. — Cover with rubber tissue a flower pot in which a vigorous rubber plant or geranium is growing, so that only stem and leaves are' exposed. Water the plant prior to covering with the rubber tissue. Then weigh the plant. Record weight. Then reweigh the plant after two or three hours. Observations. — What difference in weight do you observe? Method 2. — Water the plant, tie up with rubber tissue as be- fore, and place under a bell jar. Observations. — What collects on the inner surface of the jar? Conclusion. — 1. To what is the loss of weight due? 2. How and when does the water get out of the plant? Note. — The giving off of water in the form of vapor through the leaves is called transpiration. Problem 66 : Through which surface of a leaf does transpir- ation take place ? Materials. — Two rubber-plant leaves, vaseUne, scales. Method. — Cover the upper surface of one leaf and the lower surface of the other with vaseline. Vaseline both leaf stalks at the end where the leaves were broken off. Balance the leaves exactly on the scales and place in a sunny place. Observations. — What happens? Conclusion. — Through which surface of a leaf does transpira- tion take place ? How do you know ? Problein 67 : To determine how tJie structure of a leaf fits it for the work it has to do. Materials. — Entire leaf. Method and Observations. — Examine a leaf of maple or oak. Notice that it consists of two parts : a stem, the petiole, and a l)road expanded part, the blade. Note, also, that the })etiole leads into a number of branching veins which support the blade. Estimate the amount of green leaf surface in a plant in the room by mult ii)ly- ing the surface area of one leaf by the number of leaves on the plant. 86 PLANTS MAKE FOOD Conclusion. — 1. What seems to be one purpose of the veins? 2. Remembering that the veins contain fibrovascular bundles, the tubes which conduct fluids through the plant, determine another function. 3. How is the leaf fitted to receive light? Explain. Problem 6S : To study the microscopic structure of a leaf. Materials. — Leaf of geranium, glycerine, compound microscope, glass slides, cover glasses, needles. Diagram, page 86, Civic Biology. Method. — Remove with a needle a tiny portion of the under surface of a leaf such as the geranium, or Tradescantia, mount in water or glycerine, and examine with the low power of a compound microscope. Observations. — Note numerous small structures (stomata) scattered between the irregular cells of the epidermis. Note. — Each stoma is bounded by two bean-shaped cells, guard cells. By slight changes of shape these control the size of the openings into the leaf. Study a cross section of a leaf cut through a stoma, or a good chart showing a cross section through a stoma and a vein. Into what do the stomata open ? The outer layer of cells, the epidermis, has little chlorophyll. What function might these cells have? (Look at the walls.) Beneath the epidermis find a layer of long cylindrical cells, palisade cells. Do these contain chlorophyll bodies? Below this layer note a layer of loosely joined cells, the spongy parenchyma. Do these cells contain as much chlorophyll as the palisade cells? How are they placed with reference to the stomata? Look at the vein. Where would water pass through it? Conclusion. — Knowing what you do about the use of a green leaf to the plant, determine one use of the stomata. Drawings. — 1 . Cross section under microscope. Label all parts. 2. Part of lower epidermis showing a stoma. Problem 69 : To show the effect of light on green leaves. Materials. — Oxalis or nasturtium plants. Method. — Place oxalis or nasturtium plants near a window. PROBLEM 71 87 Observations. — After several days notice the position of tlio •blades of the leaves. Notice also the leaf stalks. Conclusion. — What is the effect of Hfjjht on leaves and stems? Note. — Evidently sunlight has something to do with the life of a green plant ; for a plant growing in complete darkness is yellow or bleached (for example, sprout- ing potatoes kept 'in darkness). Let us see if we can find out by experiment just what is the relation between light and green leaves. Problem 70: To determine the relation of light to the ])res- ence of starch in a green leaf Materials. — Green plant, black alpaca, alcohol, iodine. Method. — Place any small green plant in a dark room for 24 hours. Then cover parts of several different leaves witli strips of black alpaca. Expose to direct sunli<;lit for an hour or more. Pick off the leaves partly covered with the black cloth, take off the cloth, and place the leaves in hot method alcohol. Next wash the leaves and place them in a solution of iodine. Observations. — What happens to the leaves after placing them in the alcohol? What happens to the leaves placed in iodine solution ? Conclusion. — 1. Why do we place the plant in the dark at the beginning of this experiment? 2. What effect does sunlight have upon green leaves? How do you know? 3. What effect does absence of light have? Note. — Evidently a green leaf under certain conditions (light is one) manufac- tures starch. Let us find out another. Problem 71 : Is apart of the air a factor in starch making in leaves ? Materials. — Green potted plant, vaseline, iodine, alcohol. Method. — Treat the plant as in the last problem. After removing the plant from the dark room, vaseline both sides of two or three leaves. Place the plant in the direct sunliglit for an hour or two, then pick off the vaselined leaves and some others, marking them so that you may know them. Place in liol methyl alcohol. After the chlorophyll is removed, test both vaselined and un- vaselined leaves for starch. 88 PLANTS MAKE FOOD Observations. — Do both lots of leaves show the presence of starch ? Conclusion. — What is another factor necessary for the manu- facture of starch in green leaves? Prohle^n 72 : The need of chlorophyll for starch maJcing. Materials. — Coleus or other plant with variegated leaves, iodine, methyl alcohol. Method. — Place the plant in full sunlight for an hour or two. Test these several leaves with iodine after removing chlorophyll with methyl alcohol. Observations. — Do all the leaves show the presence of starch? Do all parts of the variegated leaves show starch ? Conclusion. — Is chlorophyll necessary for starch making? Problem 73 : To consider the leaf as a manufactory. Note. — starch is made of the elements carbon, oxygen, and hydrogen. We have seen that the roots of a plant take up soil water and we have found holes in the leaves through which gases of the air might enter. Water (H2O) would account for the hydrogen and oxygen, and carbon dioxide (CO2) will furnish the carbon and oxygen. Let us compare the leaf with a mill for making starch. The sun fiirnishes the energy to run the mill and the chlorophyll grains are the millstones. Carbon dioxide and soil water are the raw products put into the mill. Observations. — Study figures on pages 92, 93, Civic Biology. 1. What is the source of the water used in the leaf? 2. Where does the carbon dioxide come from? Trace it back to its manufacture. 3. What does the sun have to do with the work of a leaf? Conclusion. — Write a paragraph telling how starch is made in a leaf. Use the terms machinery, raw materials, manufac- tured products. Prohletn 74: To show that a £as is given off as a waste product when gj^een plants make starch. Materials. — Elodea, glass jar, funnel, test tube. Method and Observations. — Place some i^M^a under a funnel in fresh water. Then invert a test tube filled with water over the funnel. See that the tube of the funnel is completely filled with PROBLEM QUESTIONS 89 water. Place the jar in the sunH*I^x>ivpeT\tiT\e.|j V/ood T*wlp 1 Conclusion. — Write a paragraph sununing up the uses of stems to man. Problem 82 : To determine tJie value of certain ivoods. Method. — Find out as many woods as you can tliat are of value because of properties listed in the following table and record in proper colunm. See Chap. X, Hunter's Essentials of Biology, or Chap. IX, Hunter's Civic Biology. After reading your text, or taking a trip to a commercial museum, till out the table on page 98. HUNTER LAB. PROS. — 7 98 OUR FORESTS P«pei» r^cik.iTv.g I> XA. T»al> ill ty- ond ^trei\g"tK So/tiwesg of Gx^aliv Conclusion. — 1. Which woods are useful for skeletons of houses ? 2. Which are useful for trim? 3. Which are useful for paper making? 4. In general, which are more used, soft or hard woods? Problem S3 : Museum trip for study of woods. Materials. — Collection of commercial woods, or trip to a museum.^ Method and Observations. — Examine specimens of the most important commercial woods. white pine spruce black cherry tulip hemlock fir hickory walnut Note such woods as sugar maple poplar black oak cherry white oak basswood chestnut white birch Describe any six of the above, telling : (a) The region where the trees grow. (6) The shape of the leaves. (c) The color of heart and sap woods. {d) Comparative weight of the wood. (e) Rapid or slow growth. (/) Economic value. Examine a specimen of a section of any big tree, such as a California big tree. Notice the so-called annual rings in the wood. About how old was this tree when it was cut? 1 A study such as here outlined may be made at any well-equipped city museum. Work of this nature may also be done in school by means of loan collections. PROBLEM 84 99 If you go to school in New York city use this diagram for your notebook. Conclusion. — If a trip is taken, write out carefully a report of the observations made. Problem 84 : To identify coimnon trees hy the use of a hey. Materials. — Vari- ous specimens of wood with leaves on twigs ; pictures of trees, flow- ers, and fruits ; ruler. Method and Obser- vations. — Using the material and the Key on the following pages under the supervision of your teacher, make careful observations of leaves given you. Note and measure size of leaf, structure, shape, etc. Refer to the Key which follows. Doterniino whether the specimen which you have belongs under A or B. If it belongs under A, for example, then place it under 1 oi' II. Having done this, determine wliether it is (i, />, or c, then 1, 2, or 3, etc., until you hnally determine the sj)e('imen of leaf, and by it, the name of the kind of tree to which it belongs. Conclusion. — What are the names of the various trees from which you have made observations? A Diagram of the Hall coxtaimng the Jks.sli' Collection of Woods, Ameuica.v Museu.m of Natural History, New York. 100 OUR FORESTS KEY TO SOME OF THE COMMON TREES OF THE NORTHEASTERN UNITED STATES The following Key was prepared by George T. Hastings of the Department of Biology of the DeWitt Clinton High School. This Key does not include the common cultivated fruit trees, or any but the commonest of cultivated shade or ornamental trees. A. Leaves, needle-shaped, or very small, scalelike. Evergreen trees, except No. 9. Conifers or Soft Woods I. Leaves needle-shaped. a. Leaves over \\ inches long, in bundles of 2, 3, or 5. 1. Leaves 5 in a cluster. 1. White Fine. 2. Leaves 3 in a cluster. 2. Fitch Fine. 3. Leaves 2 in a cluster. *Leaves 1^ to 3 inches long. 3. Scotch Fine. **Leaves 3 to 5 inches long. 4. Austrian Fine. b. Leaves about 1 inch long, many in a cluster on tiny knoblike branches. 5. Larch or Tamarack. c. Leaves less than 1| inches long, singly on the twigs. 1. Leaves flattened, growing horizontally on the twigs. *About I inch long. 6. Hemlock. ** f to 1 inch long. 7. Balsam. 2. Leaves 4 angled, growing on all sides of the twigs. *Leaves dark green, cones 4 inches or more long. 8. Norway Spruce. **Leaves bluish green, cones 1§ to 2 inches long. 9. White Spruce. II. Leaves scalelike, very small. a. Leaves rounded, overlapping, flattened on the twigs, which appear as if ironed out flat. Fruit a cone about | inch long. 10. White Cedar or Arbor Vitoe. b. Leaves sharp-pointed, on all sides of the rounded or square twigs. Fruit a small blue berry. 11. Red Cedar or Juniper. B. Leaves not needle-shaped or scalelike. Broad-leaved or Hardwood Trees I. Leaves in pairs, opposite on the branches. a. Leaves simple, palmately veined, notched or lobed. 1. The depressions between the 3 to 5 lobes narrow, acute, twigs red. KEY TO SOME OF THE COMMON TP.EKS 101 ♦Leaves notched less than halfway to the niidrih. 11'. Iiii'.s- Pert s P»,«i-»\pkii\s etc. • Orchard Fruits A-pples Apricots C K e i^r i e s ■p e. a c Vv e. ,s • Pe.ciT'* 1*1 x;iro..s Q « 1 r» c o s etc. Gt ct i.i\ S Bcji'ley C or^xv OcrtS Rice Rjy^e ^^^lvecxt etc. Miscellaneous Barvcirvtxs Coco Cf CoCon.vct Cofi e e. Cot^ t or\ Pepper^ etc. Problem 86: To learn to know some green plants Jiariiifjil to man. Materials. — Copies of Chestnut's Thirty Poisonous Plants of the U. S., Farmers' Bulletin 86, and Dewey's Two Hundred Weeds, How to Know Them and How to Kill Them, Farmers' Bulletin 17. A few of the common plants which are weeds in your locality. (Poison ivy can be studied if placed in air-tight jars.) Method and Observations. — Using Farmers' Bulletin 8(), iden- tify and give the characters by which you would know the follow- ing : pokeweed, corn cockle, black cherry, loco weed (very harmful in the West), snow-on-the-mountain, poison ivy, poison oak, poison sumac, water hemlock, poison hemlock, poison weed, black nightshade. Using Farmers' Bulletin 17, identify and classify ten of the most common weeds of eastern United States. Conclusion. — 1. Write a paragraph on some one poisonous plant and the best means of eradicating it from your vicinity. 108 RELATION OF GREEN PLANTS TO MAN 2. Make a table modeled after the following. In it place any ten plants in which you are interested. Fill out completely. ^rV'eecl ;S H cibi t cc't E 5t i iKvcited. \A/hat Keirnrt DctT\d.e 1 i o rv Catvcidct Thistle Cockle Tt3xi r» >i: ilk; vvreed. Ox ejy e D « i Sjy F> X rf %^y e e. d. lE*xjc^S'i cr TV e R cc g -^jsr eecl W^ild. Ccn-x»o"t ^ysTilcl l^ettxice • tc. Problem Questions 1. What effect ought plant products in a given locality to have on the prices of animal products having the same food value? Is this true, in your opinion ? Get your teacher to help you inter- pret this question. 2. Name ten food plants grown in your locality. 3. Name ten food plants that must be imported for our use. 4. Using the school or other museum, make a report on three different fiber plants, giving their habitat, method of manufacture from raw materials, and their ultimate uses by man. 5. Name five plants used for medicine. 6. Discuss the value of some one plant just mentioned as a specific remedy against some particular disease. 7. Show three ways in which weeds may do harm to man. Reference Books Hunter, Civic Biology, Chap. X. American Book Company. Hunter, Elements of Biology, Chap. V. American Book Company. Hunter, Essentials of Biology, Chap. V. American Book Company. Bailey, Cyclopedia of American Agriculture. The Macmillan Company. Bailey, The Evolution of our Native Fruits. The Macmillan Company. REFERENCE BOOKS 109 Bcrffen and Caldwell, Practical Botany. Ginn and Company. Beif^en and Davis, Principles of Botany. Ginn and Company. Coulter, Plant Life and Plant Uses. American Book Company. Coulter, Barnes, and Cowles, A Textbook of Botany, .\moripan Book Company. Dunn, Remedies for the Beef Famine. Literary Digest, p. 773, April 4, 1914. Gannett, Garrison, and Houston, Commercial Geography, Chtip. IX. American Book Company. Georgia, A Manual of Weeds. The Macmillan Company. Huntington, Poisonous Vagrant Weeds. House and Garden, September, 1909. Kramer, Applied and Economic Botany. B. G. Smith. Needham, Natural History of the Farm. Corastock Pul)lishing Company. Sargent, Plants and Their Uses. Henry Holt and Company. Sharpe, A Laboratory Manual in Biology. American Book Company. Toothaker, Commercial Raw Materials. Ginn and Company. U. S. Dept. of Agriculture, Farmers' Bulletin 86, Thirty Poisonous Plants of the United States, V. K. Chestnut. Bulletin 17, Two Hundred Weeds, How to Know Them and How to Kill Them, L. H. Dewey. Bulletin 295, Potatoes and Other Root Crops as Food. Bulletin 132, Nuts and Their Use as Food. XL PLANTS WITHOUT CHLOROPHYLL IN THEIR RELATION TO MAN Problems, — {a) How molds and other saprophytic fungi do hajnn to man. (b) What yeasts do for manlcind. (c) A study ofhacteida with reference to (i) Conditions favorable and unfavorable to growth. {2) Their relations to manlcind. {3) Some methods of fighting harmful bacteria and dis- eases caused by them. Laboratory Suggestions Field work. — Presence of bracket fungi and chestnut canker. Home experiment. — Conditions favorable to growth of mold. Laboratory demonstration. — Growth of mold, structure, drawing. Home experiment or laboratory demonstration. — Conditions unfavor- able for growth of molds. Demonstration. — Process of fermentation. Microscopic demonstration. — Growing yeast cells. Drawing, Home experiment. — Conditions favorable for growth of yeast. Home experiment. — Conditions favorable for growth of yeast in bread. Demonstration and experiment. — Where bacteria may be found. Demonstration. — Methods of growth of bacteria, pure cultures, and colonies shown. Demonstration. — Foods preferred by bacteria. Demonstration. — Conditions favorable for growth of bacteria. Demonstration. — Conditions unfavorable for growth of bacteria. Demonstration by charts, diagrams, etc. — The relation of bacteria to disease in a large city. To THE Teacher. — In these days when the application of biology to human welfare is so often made the chief aim of a course in biology, it is refreshing to know that there are teachers left who beheve in logic and in the building of a super- structure before proceeding to work upon the top of the building. In point of interest and of instructive value, the exercises which follow are vital ; as experi- ments, however, they are not always absolutely to be relied upon. The extreme delicacy with which some of the factors work, the fact that we are dealing with microorganisms which cannot be handled except in bulk, the fact that most school laboratories have neither equipment nor means to obtain some of the necessary materials, make absolutely accurate experiments sometimes out of the question. 110 PROBLEM S7 111 The method of science can, however, be used and all reasonable r;ire and acm- rary 1)0 given in the perforinauee of any experiments which follow. The informational content is certainly of the widest possible importance. An entire course could well be devoted to the numerous experimental questions which present themselves. It is unwise, however, to give more than a month to six weeks' time to the chapter because of the need for balance in the course. Materials for the study of bacteria (nutrient agar or gelatine) may be obtained from any good chemist, from manufacturing chemists, and from the local board of health. Directions for making culture media follow in this chapter, but the work need not be given up because of lack of proper apparatus or laboratory facil- ities. JProblem S7 : To determine the relation of fungi to the de- struction of certain trees. NOTE. — Suggestions for field trip to work out loss of trees by the attack of shelf fungus and chestnut canker. A field trip to a park or grove near home may show the great destruction of timber by these means. a. Shelf Fungus Observations. — Count the number of perfect trees in a given area. Compare it with the number of trees attacked by the shelf fungus. Does the fungus appear to be transmitted from one tree to another near at hand? In how many instances can you discover the point where the fungus first attacked the tree? Do healthy trees seem to be attacked ? Conclusion. — Under what conditions will shelf fungus attack a tree? b. Chestnut Canker Note. — Chestnut canker is spread by tiny reproductive bodies called spores. These, if they obtain a foothold on a sound tree, soon grow to form plants which feed upon the tree, ultimately causing its death. Observations. — In a given area are all the chestnut trees dead or dying? How might tiny spores get from one tree to another? What appears to be the first sign of the disease in a tree? Pull off the bark of an infected tree and note the silvery threads running in every direction. These form the body of the canker called the mycelium, which reaches out after food. What part of the tree would it be likely to attack and why? NOTE. — A plant or animal which lives at the expense of another living plant or animal is called a parasite. Is the canker a parasite ? 112 PLANTS WITHOUT CHLOROPHYLL Conclusion. — 1. What will a parasite eventually do to the host on which it lives ? 2. Why is chestnut canker an enemy to man ? 3. Why is it so difficult to combat ? Problem 8S : To determine the conditions favorable for tlie growth of mold. Materials. — Four wide-mouth jars or bottles, bread. Method. — Place a piece of bread in each of the four wide-mouth bottles or jars, add a little water, and expose all four to the air of the living room or kitchen for half an hour. Then cover all the jars and plunge one into boiling water for a few moments; place this and a second jar side by side in a moderately warm room. Place the third jar in the ice box and the fourth in a hot and dry place. Observations. — 1. Notice day by day any changes that occur in the contents of the jars. 2. In which jar does growth appear first? 3. Do all jars have a like growth of mold at the end of a given period of time? Conclusion. — 1. How does the mold get on the bread? 2. Where does it come from? 3. Why did we add water to the jars? 4. What conditions must you have for the growth of mold ? 5. Conversely, how would you keep molds from getting a foot- hold on foods ? Problem 89: To study the structure of bread mold. Materials. — Bread mold. Figure page 133, Civic Biology. Note. — Directions for Growth of Mold. — Bread mold may be conveniently grown for laboratory use in small shallow dishes (Syracuse watch glasses, Petri dishes, or butter chips). If bread is exposed to the air for a few minutes and then left in the covered dishes for a day or two, with a bit of wet sponge or blotting paper in the dish to keep the air moist, a good supply of mold may be obtained in a convenient dish for observational purposes. Observations. — Examine the tangled mass of threads which cover the bread. This is called the mycelium, each thread being called a hypha. How do the hyphse appear to be attached to the bread ? PROBLEM 90 113 Note. — Somo of these (hroads rcticli down into the broad and art as iu.)i.->. di- gestinf^ and alxsorbing nouri.shmonl. These arc called rhizoids. Many oy A.ir of Schoolroom ©/"ScKool Quiet Hell c o/ School . Bxcsy-City e E-tc Problem 99 : To study how ra])i(lly hnrteria grow. Method. — Imagine that you have inhaled a germ causing cold or consumption {bacillus tuberculosis) while riding on the subway train or street car at 8.30 a.m. You arc in such poor physical condition that the bacterium can grow and inultii)ly. Scientists who have studied germs (bacteriologists) tell us that tiie bacterium 120 PLANTS WITHOUT CHLOROPHYLL causing consumption divides every half hour. Make the following table complete for 24 hours, using numbers only. 8.30 AM* <^ Lctctcrii£JTv tctlceiv. ii\^ *-* =1 9.00 " tke •• div-ldes V— ^ ,2 9 30 " tKe Lctctericr cLiv-icie agaiiv — — , , ^- = zj 10.00 '• "'^^ " ^--5 10.30 " ^16 11.00 •• .32 11.30 •' -64 12.00 M- =128 12.30P>1- --Z56 etc ., ». Conclusion. — 1. How many bacteria would there be in your lungs at 8.30 a.m. the following morning? 2. Why do we not catch some disease each day? We breathe, eat, and drink countless dangerous bacteria every day. (See page 154, Civic Biology.) Problem 100: What foods are preferred hy bacteria? Materials. — Raw meat, cooked meat, white of egg, beans, Indian meal flour, cake, sugar, butter, test tubes, absorbent cotton. Method. — Moisten all of the above food substances, place in test tubes with a little water. Expose all to the air for half an hour. (This can be done during a class period.) Plug with absorb- ent cotton and allow to stand for several days. Observations. — Note the appearance and odor of the various substances after five days. Conclusion. — 1. In which substances was there rapid growth of bacteria? 2. Can you make any generalization with reference to the class of nutrients most favorable for the growth of bacteria? I*rohlem 101 •' What effect has heat upon the growth of bacteria ? Materials. — Test tubes, bouillon. Method. — Number four tubes containing bouillon. Place PROBLEM 103 121 number 1 in the ice box, num})cr 2 in a dark box at a moderate tem- perature, number 3 in a box at a hot temperature (100° F. or over), and boil number 4 for 15 minutes and then place with number 2. Observations. — In which tube does the greatest amount of growth take place? (Note the odor as well as color of bouillon.) In which tube did the least growth take place? Conclusion. — What is the effect of intense heat upon bacteria? From this experiment we derive the very important mothnrl of fighting bacteria by means of sterilization. From experiments already performed give a definition of sterilization. Problem 102: To note the effect of moisture and drjjness upon the growth of bacteria. ( Home problem. ) Materials. — Beans, test tubes. Method. — Take two beans. Remove the skin and crush one. Soak the second bean overnight and then crush it. Place in test tubes, the first dry, the second with water. Leave both in a warm place for two or three days. Then smell each tube. Conclusion. — 1. In which is decay taking place? 2. In which tube are bacteria at work ? How do you know ? Note. — Heat and dryness are thus shown to be unfavorable to the growth of bacteria. From experiments dry sterilization, if continued long enough and if the heat is sufficiently high, seems the more eflfective. Some foods are spoiled by too great heat. Milk, in particular, is changed by boiling so as to be quite a different food. Hence a method of killing germs known as pasteurization is of importance. Problem 103 : To determine tlie effect of pasteuri z option upon the keeping quality of milk. Materials. — Milk, two sterilized covered jars, thermometer, double boiler, or pasteurizing apparatus. Method. — Place half of the milk in a sterilized jar, cover, and leave in a warm place for 24 to 48 hours. Place the remainder of the milk in the other jar, cover, and put it in the double boiler or pasteurizing ai)paratus. Bring the hot water suriounding the jar from 160° to 180° F. for about 30 122 PLANTS WITHOUT CHLOROPHYLL minutes. This is known as pasteurization. Afterwards treat exactly as you did the first jar of milk. Observations. — What is the odor of milk in each jar after 24 and 48 hours? What is the taste of the milk in each jar after 24 and 48 hours? Conclusion. — 1. What are found in milk that cause it to sour? How do you know? 2. What is the use of pasteurization? Problem 104 : How to care for milk bottles at home. Materials. — Recently used milk bottles. Method. — Place a recently used milk bottle in a warm place for 24 hours. Note the odor. Rinse out a second milk bottle with cold water, a third with boiling water. Set aside and note odor after 24 hours, as before. Observations. — Describe the odor. Note any differences in odor in the three bottles. Conclusion. — How should milk bottles be treated to prevent rapid souring of milk ? Problem 105: To determine the bacterial content of milh. Materials. — ^ Sterile Petri dishes containing agar culture media, a sample of milk. Method. — Milk should be collected by pupils from some near-by source as, for example, the lunchroom of the school. To 1 c.c. of this milk add 19 c.c. of distilled water in a sterile pipette. Shake well and then flood the surface of a sterile Petri dish with the mix- ture. Pour off all excess fluid. Then cover quickly and place the dish in a moderately warm place. Observations. — Notice that after 24 hours (or even less if the temperature is warm) colonies of bacteria appear on the surface of the culture media. Note the number of colonies of bacteria present on the second, fourth, and sixth days after preparing the experiment. Conclusion. — 1. What can you say of the number of bacteria in this milk ? 2. What do bacteria do to the milk ? (Smell the Petri dish.) PROBLEM 106 123 Note. — A similar experiment should be tried with water from various sources. Hot (led (IrinkiiiK water, rain water, artesian well water, tap water, and water collectod from surface pools are suggested for possible experiments. Pf^obletn 100 servatiues. To determine sortie of tlie most effective pre- Materials. — Test tubes containing beef bouillon and various preservatives, salt, sugar, vinegar, formalin, boracic acid, alcohol. Method. — Expose the tubes to the air unplugged. Number the tubes and label them. To No. 1 add nothing. No. 2 add J spoonful of salt. No. 3 add 1 spoonful of sugar. No. 4 add a saturated sugar solution. No. 5 add 1 spoonful of vinegar. No. 6 add a few drops boracic acid (saturated solution). No. 7 add | spoonful boracic acid. No. 8 add 5 drops formalin. No. 9 add 1 spoonful alcohol. Observations. — Note the appearance, odor, and color of each tube at the end of three days, five days, one week, and two weeks. Tabulate your results as shown in accom- panying chart. Conclusion. — 1. What are the most ef- fective preservatives? 2. Which of the above are permitted bylaw? (See Hunter's Civic Biology, p. 148.) 3. On which solu- tions did mold grow? 4. Which preservatives prevented bacteria but not molds? 5. Which preservatives prevented the growth of l)oth bacteria and molds? Appeararvce anjO. Odor "1 i> I 1;: 5tC- •s a. s At £nd ?/ 3 Hays At End 5 ^ays At End 1 Week At End 2 "Weeks 124 PLANTS WITHOUT CHLOROPHYLL Prohleni 107: To determiiie the most effective disinfectants. Materials. — Use tubes of bouillon containing different strength solutions of formalin, lysol, iodine, carbolic acid, and bichloride of mercury. Method. — Expose all tubes unplugged to air, having previously inoculated each tube with germs from a Petri dish culture. Num- ber and label tubes. To tube 1 add 1 drop formalin. 2 add 5 drops formalin. 3 add 1 drop lysol. 4 add 3 drops lysol. 5 add 1 drop iodine. 6 add 5 drops iodine. 7 add 4 drops carbolic acid. 8 add 10 drops carbolic acid. 9 add 1 drop bichloride mercury solution. 10 add 5 drops bichloride mercury solution. Observations. — Tabulate daily for a week or more the results for the contents of each tube on a table as shown below. Conclusion. — 1. Which of the above is the best disinfectant? Why do you answer as you do ? (Remem- ber that according to definition an antisep- tic may retard the growth of bacteria but will not of neces- sity kill them ; a ger- 77iicide destroys all bacteria if used prop- erly; while a disinfect- ant is a solution used to kill disease germs, usually in the excreta of sick people.) 2. Using the data from the last two problems, classify the materials used, as antiseptics, germicides, or disinfectants. Give reason for each. V\ppearancc Octoi- at tke E i\d of OS H 1^ ft." ?5 «0M .'S 3 d.ayg 5 d-ctyfi l"week 2 v^eeks REFERENCE BOOKS 1 25 MOUD Yeast Bacteria Drawiriid Size Conditions Favorable ForGrov/lh Conditions Harinful ToGrov/th Use to Man Harm to Man Problem Questions 1. Fill out the accompanying comparative table : 2. Where may mold spores be found? What must they have in order to grow? 3. On what part of foods do molds grow? 4. How would you prevent mold spores from getting into food? 5. Is food that has become moldy fit to eat ? Explain . 6. Why are we able to eat moldy jelly after removing the mold? 7. How may molds be harmful to man? Useful to man? 8. How may yeasts be useful to man? 9. Where are yeasts found? Give proofs, 10. What products are formed when bread rises? What be- comes of these products? 11. It is said that yeast plants are at once the friends of man and yet make him their slaves. Explain what this means. 12. Why do we place foods in the ice box? 13. Why are some meats and fish salted? 14. Why are some meats and fish smoked? 15. Why is corn, wheat, or other grain stored in a dry place? 16. Why do canned goods keep? 17. Why are preserves sometimes not fit to eat? 18. Why do we place eggs in salt, liquid glass, or coat them with paraffin in order to keep them ? 19. How would you prevent milk from souring? 20. What would you do to prevent the possible spread of laivts Gre.e.*v Ixvc OTixe of A.nirr»als /rom Bacteria Owtgo oj AlA I IIX C\\ fi to rrohlem 111: To prove a hay infusion is an unbalanced aquarium. Materials. — Hay, glass jar, microscope, glass slides, cover glasses, and pipette. HUNTEK LAB. PUGB. 9 130 THE RELATIONS OF PLANTS TO ANIMALS Method. — Make ii hay infusion by placing a wisp of hay in a jar of wafni wntcM". Lot it stand a few days. Observations. — What has happened to the hay? Any change in color? Appearance? Odor? What do you know has hap- pened to materials within the hay infusion? With a l)ulb pipette take a drop of water from the edge of the jar near the surface of the water. Place it on a glass slide. Examine with the low power of the compound microscope. The tiny structures moving about are one-celled animals. Grass for hay is often cut near pools that dry up at haying time. These pools contain millions of one-celled animals (Protozoa) which, as the pond dries up, proceed to form a heavy wall about each tiny body. In this form (like spores of mold) they may be blown about in dust and still retain their vitality. Conclusion. — 1. What does the presence of decay in the hay infusion indicate? 2. How do the Protozoa get in the infusion? 3. On what might the Protozoa feed ? 4. Why is the hay infusion unbalanced? 5. How long might life exist in it? Problem Questions 1 . Why is an aquarium called balanced f 2. What factors are necessarj^ for the balance? 3. What are the food relations existing between plants and animals in an aquarium ? 4. Compare life on the earth to a balanced aquarium. 5. What kinds of bacteria are necessary to life on the earth? Why? 6. What substances are formed through the influence of the bacteria of decay? 7. What is meant by the carbon cycle? 8. What do you understand by the oxygen cycle? 9. Explain the nitrogen cycle in an aquarium; on the earth. 10. W^hat are the indispensable bacteria? Why? n. In what stage must the one-celled animals have been when they were attached to the hay ? Why ? REFERENCE BOOKS i:il Reference Books Hunter, Civic Biology, Cliap. XII. American Book Company, Hunter, Elements of Biology, Chap. XII. American Book Company. Hunter, Essentials of Biology, Chap. XI\'. American Book Company. Abbott, Elementary Principles of General Biology. The Macmillan Company. Arnold, 77(c Sea Beach at Ebb Tide. Century Company. Bateman and Bennett, The Book of Aquaria : Part I, Frcsh-watcr Aquaria; Bart II, Marine Aquaria. Charles Scribner's Sons. Bateman, The Vivarium. Charles Scribner's Sons. Calkins, Biology. Henry Holt and Company. Eggeling and Ehrenberg, The Fresh-water Aquarium and its Inhaftitants. Henry Holt and Company. Furneaux, Life in Ponds and Streams. Longmans, Green and Company. Hail, The Soil as a Battle Ground. Harper's Magazine, October, 1910. Jones, The Aquarian Naturalist. Van Voorst, London. Kellogg, Elementary Zoology. Henry Holt and Company. Mayer, Seashore Life. The New York Aquarium Nature Series, 1905. Murbach, Fresh-water Aquaria. .Journal Applied Alicroscopy, September, 1900: also American A^aturalist, March, 1900. Nevins, The Balanced Aquarium. Pearson's Magazine, October, 1907. Parker, Biology. The Macmillan Company. Rogers, The Salt-water Aquarium,. Country Life in America, July, 1904. Rogers, Life in an Aquarium,. Teachers' Nature Study Leaflets, No. 11, Cornell University, April, 1898. Samuel, The Amateur Aquarist. Baker and Company. Sedgwick and Wilson, Biology. Henry Holt and Company. The Care of Balanced Aquaria. New York Zoological Society Bulletin for April, 1903. Whedon, The Fresh-water Aquarium. Country Life in America, January, 1905. XIII. SINGLE-CELLED ANIMALS CONSIDERED AS ORGANISMS Problems, — To deterinine : (a) How a one-celled animal is hifiuenced hy its environ- ment. (b) How a single cell perforins its function. (c) The structure of a single-celled animal. Laboratory Suggestions Laboratory study. — Study of paramoecium under compound micro- scope in its relation to food, oxygen, etc. Determination of method of movement, turning, avoiding obstructions, sensitiveness to stimuli. Draw- ings to illustrate above points. Laboratory demonstrations. — Living paramoecium to show structure of cell. Demonstration with carmine to show food vacuoles and action of cilia. Use of charts and stained specimens to show other points of cell structure. Laboratory demonstration of fission. To THE Teacher. — With the introduction given by the previous chapter, it is easy to demonstrate some o£ the reactions of a single-celled animal, and compare them with those of a single-celled plant. The structure of a cell and its various functions as an organism make this chapter of great interest to all pupils, espe- cially as the wonders of the world of the microscope are placed at their disposal. Problein 112: To study a one-celled animal in order to understand better {a) its reactions to stimuli; ib) the cell as a unit of structure. Materials. — Hay infusion, pipette, glass slides, cover glasses, and compound microscope, Kny or Leukart charts. Method. — Remove, by means of a pipette, a few drops of the whitish scum on the top of the hay infusion. This scum contains great numbers of pararnoecia (a one-celled animal). Moimt on a slide with a little spirogyra or other green alga. After allowing slide to stand for a few moments, examine under the low power. 132 PKORLE.M 112 i:« a. Reaction to Stimuli Observations. — Do tiie moving structures appcur to luivc any definite shapes? Do they move with any definite end forward? Do they collect in any locality ? If so, what influences them to do this? Heat a needle and introduce at one side of the cover ji;lass. Any movement on the part of the paramoecia? Notice some of the animals grouped around masses of food. Why do you suppose the paramoecia are there? Notice other paramoecia with refer- ence to the position of air bubbles or to threads of spiro^yi-a. How do they He with reference to the air bubble? What mi^ht the animal get from the air bubble if it is to do work? How would a cell covered with a membrane take anything from an air bubble? What might it give in exchange? Note. — All things that influence a plant or animal to react are called stimuli. Conclusion. — 1. Write a paragraph explaining how a para- moecium reacts to the stimuli in its environment. 2. Make drawings to illustrate your conclusions. b. Movement Observations. — Look at the chart or at the prepared material for tiny projections from the body walls of the jxiranuecium. These structures, which are flexible threads of living matter, are called cilia. Conclusion. — How might locomotion be accomplished by means of cilia? Explain with the aid of a diagram. c. Internal Structure Observations. — To study the internal structure of jjaramaH-ia use living animals which have been fed on green microscopic plants or on carmine grains. Examine^ with high |)ower and also use charts. The small round spaces filled with green plant mate- rial or with red carmine grains are food racuolcs. Look for a groove on one side of the cell; this leads into a funnel-like oi)ening, the gullet (g). (See page 134.) Explain how food might be takcMi in by a paramoecium. How might it circulate within tlu^ body? 134 SINGLE-CELLED ANIAL\LS AS ORGANISMS i^iw-oelD ex 71 '■:Tkr'4 "'l"""" P* cir» ct rrv oe oi ^trrv "Voi^t ic ell cc Remember that the paramoecium is a semi-fluid body, covered with a membrane. Other structures found within the cell are (1) contractile vacuoles (cv) , usually one at each end of the cell ; these serve to excrete liquid waste ; (2) water vacuoles, clear spaces; (3) the nucleus (n), con- sisting of a double structure, the micro- and the macro-nucleus which can be seen only in a stained specimen. (Demonstra- tion.) Conclusion. — L What struc- tures are found in a one-celled animal ? 2. What uses have these struc- tures ? 3. Draw a paramoecium show- ing all structures. A Colonial Type d. Reproduction Observations. — Sometimes paramoecia may be found divid- ing crosswise by fission. In this process each of the two new cells formed contains half the original nucleus and half of the rest of the cell body. Draw such a specimen if 3^ou find one. In another method of reproduction, parts of the nuclei of two adjoining cells become exchanged, so that the first cell has part of the nucleus of the second cell and the second cell has part of the nucleus of the first cell. This is known as conjuga- tion. Conclusion. — L How do paramoecia reproduce? 2. What is the difference between fission and conjugation? REFERENCE BOOKS 135 Problem ll'i : Cm)V])aratJve stitfhjof rarious fnmvfiof siti^le- ceUecl atUmals to cxplaiiv division of labor. (Kxtra Problem.) Materials. — Figures on opposite page showing amoeba, paranioe- cium, vorticella, and a colonial form, such as charchesium or zoo- thamnium. Observations. — Examine the figure of an amoeba. Are there any special structures for locomotion? The entire cell body changes shape as the animal moves. Has the animal any definite mouth? Gullet? Look at the figures. How is food taken into the body? Look for food vacuoles, contractile vacuoles, nucleus. Compare an amoeba with a paramoecium. In which cell is the work performed by more separate parts of the cell ? NOTE. — The performance of different kinds of work by dififercnt structures in a plant or animal is called division of labor. Compare the amoeba and paramoecium with vorticella. Note the stalk; it is contractile. Is the entire body covered with cilia? Are the cilia used for the same purpose as in paramoecium ? Is there a definite food opening? How does food get into this opening? (Demonstration of a vorticella in a weak carmine mix- ture will show this point.) Look at the colonial form. How does it differ from vorticella? How does it move? How is food obtained? Is there greater or less division of labor than in a single cell ? Conclusion. — What is division of lal)or? Explain from com- parison with at least three one-celled animals. Problem Qu?:stions 1. Explain the term " reaction to stimuli " with reference to paramoecium. 2. What parts of a cell are found in paramoecium ? 3. How does paramoecium move? Feed? Breathe? Re- produce ? 4. How is division of labor illustrated among the Protozoa? Refehence Books Hunter, Ciinc Biology, Chap. XIII. AmericMM iiook ('()mi»:tiiy. Hunter, Elements of Biology, Chap. XII. American Book Company. 136 SINGLE-CELLED ANIMALS AS ORGANISMS Hunter, Essentials of Biology, Chap. XV. American Book Company. Calkins, Protozoology. Lea and Febiger. Calkins, The Protozoa. The Macmillan Company. Davison, Human Body and Health, Advanced, Chap. XXIII. American Book Company. Guyer, Animal Micrology. University of Chicago Press. Jennings, Study of the Lower Organisms. Carnegie Institution Report. Jordan, Kellogg, and Heath, Animal Studies. D. Appleton and Company. Macfadyen, The Cell as the Unit of Life. P. Blakiston's Son and Company. Parker, Lessons in Elementary Biology. The Macmillan Company. Ritchie, Primer of Sanitation, Chap. XXVI. World Book Company. Shannon, The Microscopic Animals of the Sea. Harper's Magazine, June, 1910. Sharpe, Laboratory Manual in Biology, pp. 140-143. American Book Company. Wilson, The Cell in Development and Inheritance. The Macmillan Company. J XIV. DIVISION OF LABOR. THE VARIOUS FORMS OF PLANTS AND ANIMALS Probletns. — The development and forms of jilants. The development of a simple animal. What is division of labor ? In what does it result ? How to know the chief characters of some great animcd groups. Laboratory Suggestions A visit to a botanical garden or laboratory demonstration. — Some of the forms of plant life. Review of essential facts in development of bean or corn embryo. Demonstration. — Charts or models showing the development of a many- celled animal from egg through gastrula stage. Demonstration. — Types which illustrate increasing complexity of body form and division of labor. Museum trip. — To afford pupil a means of identification of examples of principal phyla. This should be preceded by objective demonstration work in school laboratory. To THE Teacher. — The object of this chapter is to Rive the pupil a bird's-eye view of the plant and animal kingdoms. This is not done for the sake of accurate classification, but simply to impress him with the wonderful diversity and com- plexity of form and structure in the living world about him. Also those exercises should bring home the idea that division of labor and complexity of structure in plants and animals go hand in hand. The exercise in determining the place of animals and plants in the evolutionary scale should be largely an exercise in deter- mining the amount of division of labor shown in a given group. It is needless to say that the work can best be done by means of typo collections in a museum or in the laboratory. The outline (Problem US) in the hands of the pupils aids in the identification of the various phyla. Comparison of type forms under these phyla gives the pupil an excellent opportunity for study of relation of forms. Problem 114: How the plant kingdom is classified. Materials. — Specimens of algae, fungi, mosses, ferns, and flowering plants. Note. — All animal and plant life shows greater <»r le.s.s divi.sion of lalior. the more complex forms showing greater division of labor. We classify as hightr the plants or animals showing greater division of labor. 137 138 DIVISION OF LABOR a. Algae Method and Observations. — Examine some pond scum with a hand lens. What kind of body has the plant? Has it any root, stem, and leaves? Look at specimens under the microscope and on the chart to determine the methods of reproduction. Conclusion. — 1. Would such a plant as this have much divisi'on of labor? Many different organs? 2. How does such a plant reproduce ? b. Fungi Method and Observations. — You have already studied a yeast and a mold as examples of fungi. Study in addition a shelf fungus. Remember that the shelf-like part is the reproductive portion (much like the sporangium and stalk of black mold). Study a piece of decayed wood containing mycelium of bracket fungus. What is its general appearance ? Compare with mycelium of mold. Conclusion. — Is division of labor greater in the algae studied or in the fungi studied ? Explain fully. c. Mosses Method and Observations. — Notice that the body of the moss shows rootlike structures, rhizoids ; an upright stem ; and leaf- like structures. Notice that some bear stalks with a little capsule on the top. The stalk and capsule bear asexual spores and are known as the asexual generation. The moss plants produce egg and sperm cells in different organs, giving the title of sexual generation to this part of the plant. Conclusion. — ■ Does the separating of the plant into two phases, a sexual and an asexual phase, result in greater or less division of labor? Explain. d. Ferns Method and Observations. — The fern plant has roots, an underground stem, and large leaves called fronds. On the backs of some of the fronds are found asexual spore-producing bodies, sporangia. The sexual part of the fern (see chart) is a very tiny body called a prothallus. PROBLEM lir, IM) Conclusion. — ronipiire the ferns with other plants in com- plexity of structure. e. Flowering Plants Method and Observations. — In the llo\verin«i i)lants the sexual generation is reduced to a very small part of the flower, the stamens and pistil. What structures found tlierein make tliis the sexual generation? All the rest of a plant — root, stem, leaves — is the asexual generation. Conclusion. — 1. Compare the various structures of a llowering plant with those of the fern, moss, fungus, and alga. 2. Show that division of labor is greatest in tlie flowering plant. f. Physiological Development Refer back to your work on the function of the flower. At the time of fertilization, how many cells make up the young plant? What happens to it as it grows into an embryo ? Is an embryo a more complex structure than an egg? Why? Tn the above forms is the development of this young plant in any way similar? (See charts or text figures.) General Conclusion. — 1. What group of plants studied has the most complex structure? The greatest division of labor? 2. Is there any connection between the position of a jilant in the plant kingdom and its complexity of structure? Explain. Problem 115: To compare reproduction in plants witli that in animals. Materials. — Charts and models illustrating processes of fertilization and development in plants and animals. Method. — Compare, by means of charts, fertihzation in several types of plants with that in some simi)le animal. Use models illustrating early development of amphioxus, fish, and frog. Observations. — How does fertilization take place in a flower- ing plant? In a fern? In a moss? In a very simple i)lant ? By what means does the sperm cell get to the egg cell in each of the above cases? Is there any outside agency that helps in this? 140 DIVISION OF LABOR NOTE. — In animals, as in plants, two cells, the sperm and the esp:, unite to form a fertilized egg. This cell will, under favorable conditions, develop into a uew animal. In animals, which is the larger, sperm or egg cell ? Which is the movable cell? Suppose an animal, as a fish, laid its eggs in the water, how might fertilization take place? NOTE. — The embryo of a plant (e.g., the bean seed) grows as the result of the division of the original fertilized egg into first two, then four, then eight, etc., cells. An animal embryo develops in a similar manner. Arrange models in order to show development from a single cell (the fertilized egg) to a hollow ball of cells, called the blastula stage. (See figures above.) Note what happens next in develop- ment. The cup-like structure is called a gastrula. How is the gastrula stage formed? NOTE. — Most animals, including man, pass through the stages shown above. Suppose that all the cells had ciHa in the blastula stage. How would locomotion take place ? Suppose the hollow of the gastrula is used as a food tube. Is there then any division of labor? Conclusion. — 1. In what respects is fertilization similar in plants and in animals? 2. What stages of development are alike in all animals? Problem JIG: To study the division of labor in tissues and organs. Materials. — Charts and slides showing different kinds of tissues, microscope. Method and Observations. — We have already found that cells having the same structure and performing the same work form tissues. Examples in our bodies are muscle tissue, nerve tissue, connective tissue, etc. Does a blastula have more than one tissue? A gastrula? Give reasons for your answers. Examine figure, page 179, Civic Biology, or slides showing different PROBLEM 118 111 kinds of cells, such as muscle, nerve, and l)one. Why do we have different tissues in a plant or in an animal ? Note. — The hand is an organ, a structure made up (jf different tissues, all of which work together for the performance of certain work. Name some organ found in an animal; in a plant. Name some tissues that make up your hand ; your foot ; your eye. (Use your Civic Biology, pages 266-271, for this purpose.) Conclusion. — 1. Why are cells of different shapes and sizes? 2. Of what purpose are tissues in our body? 3. Why are organs composed of tissues? Use the term division of labor in writing your answer. Probletn 117 : To find some of the functions common to all aniinals. Method. — Review the needs of a single-celled animal. What must a single-celled. animal do in order to live? NOTE. — Remember that food must be obtained, digested, and oxidized to re- lease energy (in a many-celled animal this food must be circulated about the ani- mal). Some of it must be made into living matter, and wastes must be excreted from the body. What organs has a single-celled animal that perform each of these functions? Compare the needs of a paramoecium with (mr needs. Compare the functions of a paramoecium with our func- tions. Compare, in each, the organs which perform these func- tions so far as you know them. Get assistance from j-our text- book {Civic Biology, pages 180, 181). Conclusion. — How does a single-coll(Ml animal compare with a very complex animal in the number of function.s and in tlie organs it has for performing these functions? Problem US' How to know some tyf)es of animcils in the animal kingdom. Materials. — Dried or formalin spiM-imens of sponge, se^i anemone, starfish, segnuMited worms, crust a('(>ans, iiiscM'ts, mollusks, and vertebrates (fish, frog, turtle, l)ird, and manunal). 142 DIV1810N OF LABOR Groups of Animals Note. — Animals may be arranged in an e\'olution£.ry series beginning with simple forms and ending with very complex forms, such as man. Division of labor in a steadily increasing degree is seen as we go from the simple to the higher forms. We shall try to arrange the forms given in an evolutionary series, beginning with the simplest forms and working up to the most complex. a. Protozoa First would come one-celled animals, Protozoa. Name three Protozoa which you have studied. b. Porifera Sponges, Porifera (containing pores) . Examples : bath sponge, Grantia. Simple fixed forms. Note a specimen of the bath sponge. Has it a skeleton? What is the internal structure of a sponge? (See figure on page 180, Civic Biology.) c. Coelenterates Coelenterates (Coelom = body cavity, enter on = food tube). Examples : Hydra, sea anemone, jellyfish. There is a single cavity in the body with one opening. (See figure on page 179, Civic Biologij.) The animals in this group are provided with sting- ing cells. d. Segmented Worms Examples : sandworm, earthworm. Long jointed or segmented animals with or without jointed legs. Nervous system on the under side of the body. (Pages 183, 184, Civic Biology.) e. Echinoderms Examples : starfish, sea urchin. These animals have spines in the skin, body organs more complicated. (Pages 184, 185, Civic Biology.) f. Arthropods Having jointed body, jointed appendages, and outside skeleton. Nervous system on under side of the body. There are two great groups of these animals: PROBLEM QUESTIONR 113 (a) Crustacea. Limy skeleton, sej^mciifecl. Ixxly divided inlo two regions, more tlum three pairs of walkirij; appendages, breathe througli gills. Examples: erayiish, crab, lobster. (6) Insecta. Having a horny skeleton (ehitin), only three pairs of walking legs, breathe through traehea\ Examples: bee, ant, grasshopper. Two smaller groups of Aithrojxxls arc also found: the Arachnids, spiders, having four jjairs of legs, and tiu^ Myriapods, " thousand leggers," which have many pairs of simi- lar jointed legs. (Page 185, Civic Biology.) g. Mollusks Examples: clam, snail, oyster. Have a soft, unjointed body, usually covered with a hard limy shell of one or two pieces (valves). This shell is formed by a covering called the mantle. These ani- mals breathe through gills. (Page 185, Civic Biology.) h. Vertebrates Examples : fish, frog, turtle, bird, dog. Having an internal limy skeleton composed of pieces of bone jointed together. Also an external skeleton which may be scales, bone, feathers, nails, or hair. Breathe by gills or lungs. Central nervous system on back or dorsal side of body protected by a chain of bones called the vertebral column. (Pages 185-192, Civic Biology.) Method and Observations. — Using the above dinv'tions pick out of the material given you one specimen of each group and arrange the specimens selected in a series showing evolutionary order. Conclusion. — 1. What do you mean by evolutionary order? 2. Has division of labor anything to do with your placing these specimens as you have? Problem Questions 1. Why do we speak of t\w plant or animal kingdom^ 2. What results from fertilization in both plants and animals? 3. How are egg cells protected in birds? In a flower? W liy should they be protected ? 144 DIVISION OF LABOR 4. How does nature make up for lack of protection of the eggs of fishes ? (See Civic Biology, pages 238-239.) 5. What is division of labor? 6. What is a blastula? A gastrula? An embryo? Give examples. 7. What is a tissue ? An organ? 8. What are the functions necessary for all animals ? 9. How are these functions performed in a single-celled animal ? In a many-celled animal ? 10. What do we mean by evolutionary order? Reference Books Hunter, Civic Biology, Chap. XIV. American Book Company. Hunter, Elements of Biology, Chap. XVI. American Book Company. Hunter, Essentials of Biology, Chap. XVI. American Book Company. Adams, Guide to Study of Animal Ecology. The Macmillan Company. Comstock, Manual for Study of Insects. Comstock Publishing Company. Comstock, The Spider Book. Doubleday, Page and Company. Davenport, Introduction to Zoology. The Macmillan Company. Fabre, Life of the Fly. Dodd, Mead and Company. Fabre, Life cf the Spider. Hodder and Stoughton. Fabre, Social Life in the Insect World. T. Fisher Unwin. Flower, The Horse. D. Appleton and Company. French, The Butterflies of the Eastern United States. J. B. Lippincott Company. Hahn, Hiberyiation of Animals. Popular Science Monthly, February, 1914. Harmer and Shipley, The Cambridge Natural History. Vol. V. The Macmillan Company. Herrick, Household Insects and Methods of Control. Cornell Reading Courses. Holland, The Butterfly Bock. Doubleday, Page and Company. Holland, The Moth Book. Doubleday, Page and Company. Hornaday, Our Vanishing Wild Life. New York Zoological Society. Hornaday, American Natural History. Charles Scribner's Sons. Hough and Sedgwick, The Human Mechanism. Ginn and Company. Howard, The Insect Book. Doubleday, Page and Company. Kellogg, Elementary Zoology. Henry Holt and Company. Kingsley, The Comparative Anatomy of the Vertebrates. P. Blakiston's Son and Company. Linville and Kelly, Textbook in General Zoology. Ginn and Company. Maeterlink, Life of the Bee. Dodd, Mead and Company. Miall, Aquatic Insects. The Macmillan Company. Miller, Butterfly and Moth Book. Charles Scribner's Sons. Miner, Animals of the Wharf Piles. American Museum of Natural History. Miner, Sea Worm Group. American Museum of Natural History. Needham, Elementary Lessons in Zoology. American Book Company. REFERENCE BOOKS 1 i:, Parker and Haswell, Manual of Zoology. The Maciiiillari ("otiipany. Porterrf, Wild Beasts. Charles Seribner's Sons. Pycraft, Domestication of Animals. Scientific American, .Iatniar\- 10, l\tl\. Schaler, Domesticated Animals, Their Relations to Man and tu Ilia Adcanccmcnt in Civilization. Charles Scribner's Sons. vScudder, Guide to the Common Bnttcrflies. Henry Holt, and Company. Seton, Wild Animals I Hare I\.nown. Charles Sfribner's Sons. Shipley, Honeybee. Edinburgh licincw, .January, 1!)I1. Stone and Cram, American Animals. Doubleduy, Page and Conipauy. Wright, Four-footed Americans. The Macmillan Company. HUNTER LAB. PROB. — 10 XV. THE ECONOMIC IMPORTANCE OF ANIMALS Problems. — I. To determine the uses of animals. (a) Ijidirectly as food. {h) Directly as food. (c) As domesticated animals. id) For clothing. (e) Other direct economic uses. (/) Destruction ofharnifivl plants and animals. II. To determine the harm done hy animals. (a) Animals destructive to those used for food. (Jb) Animals harmful to crops and gardens. (c) Animals harmful to fruit and forest trees. id) Animals destructive to stored food or clothing. (e) Animals indirectly or directly responsible for disease. To THE Teacher. — Inasmuch as this work is planned for the winter months the laboratory side must be largelj' museum and reference work. It is to be ex- pected that the teacher will wish to refer to much of this work at the time work is done on a given group. But it is pedagogically desirable that the work as planned should be varied. Interest is thus held. Outlines prepared by the teacher to be filled in by the student are desirable because they lead the pupil to individual selec- tion of what seems to him as important material. Opportunity should be given for laboratory exercises based on original sources. The pupils should be made to use reports of the U. S. Department of Agriculture, the Biological Survey, various state reports, and others. Special home laboratory reports may be well made at this time, for example : determination at a local fish market of the fish that are cheap and fresh at a given time. Have the students give reasons for this. Study conditions in the meat market in a similar manner. Other local food conditions may also be studied first hand. This chapter is intended to be a practical resume of the use and harm done by animals. Some of the work is intended as a change from pure laboratory work to that of reference reading. But some extremely important work outlined in this chapter should be taken when the season will allow, in the laboratory, in the field, or at home. Practical work on the relation of mosquitoes and flies to disease should be part of every educated person's knowledge, for ability to deal with these pests may mean health as well as comfort in the home locality. 146 PROBLEM 119 117 Problem 119: What animal foods arc chcapcfit in any locality and wliy? (Home work.) Method and Observations. — a. Visit your local fish and moat markets. If in New York, read the publications of tlie Mayor's Food Supply Committee. Make tables of the fish and meats that Name of Fish Habitat Price for lb. Kexnarks 1. 2,. etc. 1 o/Mecl Anin»nl it ComM jrom Habitnl Ot.t .r l*urt Eat«n )..r lU R*Kark< are relatively cheap and those that are expensive. Go to the li- brary and look up in an encyclopedia or Jordan and Evermann's American Food and Game Fishes the habitat of each fish you have priced. In Hornaday's American Natural History or an ency- clopedia look up the habitat of the animals which supply the meats you have priced. Read Kipling's Captains Courageous to see how certain fish are ^_-^ obtained. h. Using the figure, locate the various cuts of meat priced at the market. You will find that the cut of meat (part of animal used) determines the price, and this price is further determined b}^ the de- ^ .'-.- mand of people buying and the sui:)ply in the market. Conclusion. — 1. Does the habitat of the animal have any- thing to do with it^ price in the market? 2. What other factors might infiuence the price uf fish? Ask your teacher to help you in this. 3. What factors might determine the price of meat ? 4. What factors largely determine the price oi cut.>< of meat? , . — ;'?K?.''»iPT^r^"-j.r5iow. »Wi-.rj:,77^ 148 THE ECONOMIC IMPORTANCE OF ANIMALS Hnbitat T/se of Products Preparat iorv oj Products OtKe-r Fatts Problem I'^O: How animals may benefit mankind. Materials. — Hunter's Civic Biology, pages 197-231, Toothaker's Commercial Raw Materials, Government and State Department re- ports of various kinds. A visit to a commercial museum. Method. — Using your sources of in- formation, make out in tabular form a report giving (1) habitat, (2) use, (3) prep- aration of product, (4) other interesting facts with reference to the following animals: cow, sheep, horse, pig, whale, walrus, honeybee, ichneumon fly, silk- worm, ladybug, tach- ina fly, gall insects, blister beetles, lac in- sect, cochineal, bum- blebee, carrion beetle, toad, house wren, cuckoo, bank swallow, bluebird, woodpecker, brown thrush, guH, vulture, owl, black snake, milk snake, green snake. Conclusion. — In what ways are the above animals useful to man? Problem 121: To find out how birds are of economic im- portance. Materials. — Pam- phlets of the Depart- V). T3 o Bobolink Blackbird Ccjtbird Coopers Hawk Cro'^^^' Ct4 ckoo D ove En glisli Sparrow a VI 11 Kiivgbird Kingj"i$Ker Ow^l, Horned PKoebe Qwail Robiix Say s ucker Starling Swallow ThrusK V7"T«e.Tv. PROIM.EM 12:] 149 ment of Agriculture (see list of Reference Books) and Civic Biohxjij, pages 209-211. Method and Observations. — I'ill oul Uk^ i)i('c('(liiig tahlc on the food of some birds, using references suggested above. Conclusion. — Which of the birds are of use to man ? ( )f harm ? Which may be of both harm and use? Explain yom- answers. Problem 122: What are the causes of decrease in tlie nuiJiher of birds ? Method and Observations. • — Using your own experience and the information obtained from Hornaday's Our Van- ishing Wild Life, complete a table like the accompanying. Conclusion. — In a care- fully written paragraph sug- gest some methods of prevent- ing the decrease of our helpful birds. Problem 123 : To study the life history of the mosquito. Note. — There are four distinct stages in the devclopinont of the mosquito: egg, larva, pupa, and adult. These will be taken up and studied in order. a. The Egg Method. — The eggs of mosquitoes are laid on the surface of still salt or fresh water pools from April to October. By placing a can of water in a lot, we can often obtain the small rafts of eggs of the connnon mos- quito, the culex, and less often the single floating eggs of the malarial mosquito, the anopheles. Any standing water, especially in barrels, old cans, neglected drains, catch basins, and swamps, may make a near-by neighborhood almost uninhabitable. The yellow- fever mosquito, stegomyia, is not found in the North but is found in the warmer parts of the United States. Factors Birds A/fected H v.^ Affected R^fnedie* Propofoci Clearing 0/ Forvjis Tultivution ofhand SlauahtfT fordame for Feat hors EggColI«>rtii\g Use as Food Cctts.V/easels, Sparrows ,Jny»,ete V '^^^^^> K 150 THE ECONOMIC IMPORTANCE OF ANIMALS b. The Larva (Wiggler) Materials. — The eggs will hatch if kept in a warm place, or wigglers can be scooped from a pond or pool of water. These may be kept in a screened battery jar half full of water. Observations. — What is the shape of the larva3? How do they move through the water? Watch the larvae while at the surface. Which end is up? (Note the breathing tube that reaches through the surface of the water.) What is the position of the larvae while at the surface? If they lie horizontal to the surface, they are the larvae of the ano'pheles, the malarial mosquito ; if at an acute angle, the larvae are those of culex, the harmless mosquito. c. The Pupa Method and Observations. — Place a number of wigglers in a screened battery jar. Allow them to cast off their skins and become pupae. How does this stage differ from the larval stage? Notice the empty shells of the pupae floating on the surface of the water. How did the adult mosquitoes get out? Do the pupae come to the surface of the water? If so, why? Compare the position of the pupae at rest with the figures. Is the mosquito a culex or an anopheles ? d. The Adult Observations. — In a hatched adult observe the number and kind of wings. In which insect group do mosquitoes belong? Notice the antennae or feelers. (The males have more bushy PROBLEM 125 151 feelers. Males do not bite.) What is the restinj^ position of the adult? Compare with the figures on page 218, Civic BioUnjij, and decide what kind of mosquito it is. Conclusion. — Write in a concise paragraph a short life history of the mosquito, either culex or anopheles. Prohleni 124: To find tlw hreedi]i^ ])Jaces of Dinsqititoes in any locality and how to destroy tJiem. Field Trip. — Plot a map of your (Ustrict showing all tin* water that might contain mosquito larvifi. Remember that tin cans in rubbish heaps, flat tin roofs or gutters, anything that can hold water for two weeks at a time may breed mosquitoes. Look (•ar(^- fully for larvae or pupffi. (^n the map note with a cro.ss where you have found them. If such localities are found, go to the householder and explain what you have found. Conclusion. — If mosquitoes can fly several hundred yaitls from their l^reeding places, is my liotno snfe from mosquitoes? ProhU'in I2r>: To dctcriniuc sontr nirfhoils of destroying mo^qnitoes. Materials. — Mosquito l;irv;r mfkI |)iip:i'. b.il 1(M\' j;ir. kerosene oil, goldfish. 152 THE ECONOMIC IMPORTANCE OF ANIMALS Method 1. — Put a few mosquito larvae and pupae in a small battery jar. Pour in a few drops of kerosene oil. Observations. — What happens to the oil and the water ? What becomes of the larvae and pupae ? Remembering that all eggs are laid on the surface of the water, what would happen to the eggs when laid? Method 2. — Place some small goldfish or sticklebacks in a jar containing larvae and pupae. Observations. — What happens? Conclusion. — Now go over the map you have made. Which of the above means would you use to exterminate mosquitoes in your locality? Prohlein 126 : To find the relation of mosquitoes to diseases of man. Note. — Malaria and yellow fever, diseases caused by tiny protozoans, are transmitted to man through the bite of mosquitoes. This is proved because men have escaped malaria in malaria-infected districts by taking precautions to have their bodies at all times protected from the bite of the mosquito. This was done by screening, by remaining indoors at times when the mosquitoes were out, and by wearing, when exposed, head nets and gloves. In 1890 two London doctors allowed themselves to be bitten by anopheles mos- quitoes which had previously bitten people who had malaria. In a little over two weeks both came down with malaria. Observations. — What causes malaria? What have swamps and stagnant water to do with malaria? Why did the people who were screened not get malaria ? Why did the London doctors get malaria? Conclusion. — What has the anopheles mosquito to do with malaria ? Problem 127 : To study the life history of the parasite caus- ing malaria. Material. — Charts, or illustration in Hunter's Civic Biology, page 217. Observations. — Note the lower part of the diagram which represents the blood tube of a man. What changes take place in the parasite within the corpuscles? What two kinds of organisms ultimately are formed? PROBLEM 128 153 zjever sta^^ Notice that the malarial parasite passes part of its life history in the body of the mosquito, and part in the human body. The lower part of the figiire rojire- sents a blood vessel in man. The parasites live part of their lives in the blood corpuscles. Then they multiply and break out of the corpuscles. (See right side of figure.) Using this figure and information from your Civic Biology, work out the complete life history of the malarial parasite. What happens if these organisms are taken into the mosquito's body ? Note. — Only when both forms of cells are taken into the body of the mo.squitt) arc the parasites able to continue their development there. Conclusion. — How might malaria be transmitted? JProblem 128 : To study tlie life history of the typhoid jly. Materials. — Raw meat, glass chshes. Method. — Expose pieces of raw beef where flies will light on them. After a few hours eovei* in glass dishes or small hatlery jars with screen covers. Observations. — Watch the meat. In pieces on which eggs wtM'c laid by the fiies describe the stages of development as they appear. Do the larvae grow any? They are called fnn(j(jols. ITow do the 154 THE ECONOMIC IMPORTANCE OF ANIMALS pupae differ from the larvae? Watch to see the adults emerge from the pupal case. How long does a complete life history take ? Conclusion. — How many generations of flies might develop during a hot summer? Problem 129 : To determ-ine the harm done by the fly and the way it does this harin. Material. — Sterile Petri dish containing culture medium. Method. — Allow a fly to walk over the surface of a sterile Petri dish with culture medium within it. Cover the dish. After three or four days examine the surface of the culture medium. Observations — What do you see? Note. — Flies breed in manure, filth of all kinds, and human excrement as well. Study a diagram showing the relation of typhoid fever to open toilets and flies in Jacksonville, Fla. (page 224, Civic Biology). Why were there fewer cases when the toilets were screened ? Study the diagram below. What relation exists between diarrheal diseases and flies? Explain. Examine the foot of a fly under the compound microscope or study upper figure, page 223, Civic Biology. What adaptations for carrying germs do you find? Infant Mortality Curve. a, prevalence of flies ; b, diarrheal under five years ; c, deaths under one year ; d, mean temperature. PROBLKAI 131 155 Conclusion. — 1. What diseases may be carried l)y flies?. 2. Where do they j;-et the germs of these diseases? 3. How do they carry these (hseases? Problem i:u>: IJluU is the best way f<» cat eh and destrmj flies? (Homework.) Materials. — Flytrap, tin plate, carbolic acid, and in.sect powder. Method and Observations. — Make a flytrap acconhn*!; to tlie plan shown ; bait it with stale fish or other fo(xl. Leave it for one day, then plunge it into boiling water and count the number of flies which you caught. Heat a tin plate containing strong car- bolic acid so that the fumes will fill a room {e.g., the kitchen) con- taining a number of flies. What results ? How does it compare with your trap ? Burn a few ounces of insect powder in a pan in the same room on another day. Compare your results with those above. Conclusion. — 1. Which is the best method of those given for destroying flies in your home ? 2. Knowing when and where flies breed, when would be the best time to '^ swat the fly"? How would this nietliod com- pare with other ways of extermination studied? An easily made Flytrap. Problem 131 : To deterviine harm done by insects. Materials. — Trips to museum, reference to texts, and various bulletins of the Department of Agriculture. Observations. — Make out in the form of the following table a report on the harm done by insects : 156 THE ECONOMIC IMPORTANCE OF ANIMALS Ncinve Harm done. Sta cse'wXen it does horm the pest 1. To gardens. — Report on cutworm, corn worm, potato beetle, squash bug. 2. To crops. — Boll weevil, chinch bug, plant lice, Hessian fly. 3. To fruit and forest trees. — Codling moth, gypsy moth, tussock moth, hickory borer, maple borer, scale insect. 4. To stored food. — Weevils, roach, ant. 5. To clothes, etc. — Clothes moth, roach. 6. As disease carriers. — Flies, mosquitoes, fleas, bedbugs. Report, using the above sources of information, on specific ways of combating one pest from each of the above groups. Conclusion. — What specific harm is done by the above-named insects and how would you go to work to prevent this harm ? JProbletn Vi2 : To hnow some forjns of animal life that cause disease. Materials. — Use your Civic Biology, Chap. XV, or any other source of infor- mation. Observations. — Fill in the accompany- ing chart, giving infor- mation with refer- ence to disease-caus- ing animals, especially hookworm, tricliina, and tapeworm. Conclusion. — 1. What animals cause disease and what dis- eases do they cause? 2. How would you attempt to cure anj^ three of these diseases? 3 . How would you attempt to prevent any three of these diseases ? Name of Disease J>iSease Caused by Diseose Carried by How to /itf^t tWtofi*]r()l)al»l\- prove of morr interest and, if seriously taken up l)\- (eaclier and pui)ils, of more lasting value than any other part of the eovu'se. 'V\\v immense siKnili<'anee of variation and heredity and the application of these factors in euKenics eertaii»ly make a theme of vital interest. The direct teaching of sex hygiene in the public sccomlary school is not recommended, both because of lack of preparation (ui the part of teachers. l>ecauso of the intimacy of contact rcciuired lietween teacher and pupil, making work with 173 174 HEREDITY AND VARIATION large groups impracticable, and because the proper place for such direct teaching is in the home. It is, however, the function of biology to teach the primary facts known about reproduction and heredity as applied in plant and animal breeding. On these facts the child of to-day will build for the experiences of to-morrow. JProhle^n 150 : To deterinine if there is individual variation in any one measurement of the members of a given class. Materials. — String, ruler. 14 15 16 17 18 19 Method. — With the string carefully measure the circumfer- ence of your right wrist. Observations. — Verify your figures by having your neighbor take the measurement for you. Do the same thing for him. The PROBLEAI 150 i:r, instructor will give you an individual numl)or. Hand in your results with your number to one pupil of the elass who will lahulate the figures on the board. Make a j2;rapli showin<;- the individual variation in circumference of the wrist in the members of your class. Conclusion. — Is there variation in this measurement amcjn^ the members of your class? 20 Zl 2^ 23 2 1 2^r NOTE. — Exercises on variation am numerons and may bo worked out from charts, from collected material showing variations, or from work done by pupils in the field. In every case where possible, a graph should be made to illustrate the normal and the variation from the normal. The exercise that follows will show the method to be used. 176 HEREDITY AND VARIATION Problem 151 : To show variation in a given class. Materials. — Figures on pages 174, 175. Later the measure- ments of the individual boys or girls of a class. a. Variation in Height Method and Observations. — Using the figures on pages 174, 175 have the members of the class place on graph paper a dot for each boy seen in the ■Number of Boy nlafp falririD- thpm in l^ 34567 89 10111213141516171819 20 212^ 23242 3 y^'^^'^J tdiviiig tllClll Hi numerical order. Connect the points made. Notice the irregularity of the hne formed. Now rearrange the boys so that the tall- est is at one end of the line and the short- est at the other end, with those of various heights graded in be- tween. Place dots on graph paper as in previous exercise. What difference do you notice in the line made? The accompanying graph shows the variation in height of the boys. But these boys differ slightly in mentality, considerably in height, considerably in weight. Is there any relation between the height and weight in a given group of boys? Note. — In the following figure the line xy represents the normal curve of weight and height relation obtained by weighing and measuring thousands of boys. ft In, 5.10 59 58 57 56 55 J.4 5.3 SZ 5.\ 5o 4U 4.10 4 9 4.8 4.7 46 14 9 15 8 5 6 17 21 3 7 16 12 IB 4 ? 23 lo 1911 22 2524 20 1 13 'S»oy-S vearrctrvgecl b. To Form a Curve Showing the Relation of Weight to Height in a Given Class Method. — Notice that a boy of 4 feet 5 inches should weigh 65 pounds, while a boy 5 feet 11 inches should weigh 170 pounds. Knowing your own height, note what your weight should be. PROBLEM 152 177 But wc find that most of us (lifTcT slijr},tly from th(Miormal and in the class represented the first boy is o feet 10 inches tall and weighs 140 pounds, while the boy numljei- 10 is l.ui .') feet 5 inches in height S'/lO'O OlflOrfl O'Oo*) o « "•OO'OOrfJ o- » and also weighs 140 pounds. Arrange your graph paper as shown at the right, with the greater weights to the left of the page and the less at the right. The heights are to be given vertically at the left side of the paper. Now pick out the members of the class and arrange them according to their weights and heights, placing a dot on the graph paper at the intersection of a given weight and height (as in the case of the boy w^ho weighs 165 pounds and who is only 5 feet 4 inches in height). After you have finished connect all the dots. Observations. — Does the line formed follow the normal curve shown in the chart (line xij) or does it vary? How do you ac- count for this? Note. — This curve you have made is called the curve of correlation l>et\veen weight and height. We might also correlate age and weight, or age and height. Conclusion. — Using the above method, make* a curve of cor- relation showing the correlation between weight and height in your own class. Problem 1!>2 : Does Jwredify ])l(nj any part in our lives ? Materials. — Statistics gathered by class demonstrations. Method. — Let each member of the class try to bring photo- graphs of his parents and if possible of their parents. Write down a list of all the physical traits oi- likenesses you can find in your own family. Bring in written or verbal reports given by your HUNTER LAB. PROB. — 12 178 HEREDITY AND VARIATION parents or, if possible, your grandparents, telling of any mental or physical characteristics they may find repeated in you from an earlier generation. Observations. — Make notes on as many striking cases of in- heritance as 3^ou can. Compare with your own case. Conclusion. — 1. Are we in any ways like our ancestors? 2. Are mental as well as physical characteristics inherited? 3. Do these characteristics seem to be the same as those in your ancestors? 4. What do we mean by heredity? JProblein 153 : To study the jine structure of an egg cell. Materials. — Egg cells, — preferably from ascaris (a worm), — stained with iron haematoxylin to show nucleus and chromosomes ; cells showing fertilization stages ; charts ; books. Observations. — Look at the stained cells each lying within a more deeply stained capsule or covering. What structure do you find within it? (Compare figure on page 252, Civic Biology.) Look for the chromosomes within the nucleus. How many can you find? Note. — The chromosomes in the cells of the body are always definite in number for every species of animal and vary from two in ascaris to over 150 in Crustaceans. In man there are sixteen. The chromosomes are believed to carry the hereditary qualities from one generation to the next. Examine stained specimens that show fertilization and study carefully the figure on page 252, Civic Biology. Note. — Before fertilization takes place, the number of chromosomes in each sperm and egg cell is reduced one half. Each cell, so far as the chromosomes are concerned, is now a half cell. Conclusion. — 1. What happens when fertilization takes place? Study the figure. 2. If new characters are brought to the new animal or plant by means of the chromosomes, then what part would fertilization play in heredity? In variation? Problem 154 : How selection is made. Materials. — Corn on ear, photographs or description of differ- ent corn plants. PROBLEM 15G 179 Observations. — Compare several ears of corn and select the ear which has most even rows, largest kernels, Qic. Suppose this ear came from a plant which had l)ut few ears. Would you select for planting-, ears from this plant or ears which were not tjuile .s(j perfect from a plant with more ears? Conclusion. — In selecting seed for planting, what are some of the factors to be kept in mind? Prohle^n 155 : A practical result of selection. NOTE. — In a government test of corn to increase the yield, ears were chosen from plants that gave a high yield and the seed planted in rows. Next year seed from these rows was planted in rows alternating with seed from orjually good-look- ing ears from the same kind of corn grown in the field. Xote the results with eight pairs of ears. Pounds of Corn yielded by the Seed of One E.\r FIELD EARS EARS FROM HIGH-YI ELDING PARENTS 170 lbs. 177.5 lbs. 139.5 " 180 139 " 199 173 " 197 154 " 172 133 " 176 156.5 " 194 153 " 200.5 Observations. — What per cent of increase was there from the selected corn? If the seed from the field-grown corn yielded 42 ])ushels per acre, what would have been the gain per acre by planting seed from the selected corn? Conclusion. — State results both in bushels and in dollars, corn being worth 75 cents per bushel. Problem 156: To determine some means of selection of fruit trees from the economic stand /joint. Method and Observations. — Given an area KHH) feet long antl 500 wide, which might be planted as follows : (1) Trees 20 feet apart, bear after five years, average fiv(* hun- dred apples per tree, continue bearing twenty-five years. Apples wholesale SI per hundred. (2) Trees 22 feet apart, bear after seven \ears, average six 180 HEREDITY AND VARIATION hundred apples, sell $1.75 per hundred, continue bearing thirty years. (3) Trees 25 feet apart, bear after six years, produce four hun- dred and fifty apples per tree, continue bearing forty years, price $2.25 per hundred. (4) Trees 18 feet apart, bear after five years, average three hundred and fifty apples per tree, bear for twenty years, average price $3 per hundred. (5) Trees 30 feet apart, bear after six years, average six hun- dred and fifty apples per tree, continue bearing twenty-five years, average price $2 per hundred. (6) Trees 24 feet apart, bear after six years, average five hun- dred apples, bearing thirty years, average price $3.25 per hundred. (7) Trees 20 feet apart, bear after four years, average two hun- dred and fifty apples per tree, continue bearing thirty years, price per hundred $3.75. Conclusion. — Which of the above would you choose to grow in the area? Give your reasons. Problem 157 : How hyhridization is accomplished in flower- ing plants. Materials. — Plants in flower, manila bags, camel's-hair brush. Method. — Tie a manila bag over a growing apple or pear bud (or any other large available flower) that is about to open. Remove from another flower of the same family, but another species, all parts except the pistil, be- fore the flower opens. Cut at fine marked W on figure. Tie a bag over it also. When the flower in the first bag opens, transfer some of the pollen to the stigma of the flower without stamens. This may be done by means of a small camel's-hair brush. Cover the surface of the stigma with pollen. Label the stigma thus pollinated, stating the date, and all data concerning source of pollen, etc. Observations. — Why do we cover the PROBLEM 150 ISl flowers in this experiment? Why such care in the transfer of pollen? What ought to happen after the transfer of the p(jllen? Conclusion. — 1. Remenihering that the egjjj cell from one flower has united with the sperm cell of anotlier flower, if the ()j)eration has been successful, what characters ought the new plant to have? Explain. 2. What is the use of hybridization? Problem 158 : Other methods used in filant breeding. Materials. — Examples of budding, grafting, layers, and slips. Charts and texts. Observations. — Notice carefully what has been done in making a tongue graft, a cleft graft. Study the steps in budding (page 256, Civic Biology). Consult any good book on agriculture to see ^PtO how layering and slipping are done. Conclusion. — 1. How might Pc \^ w^ these processes enable man (a) ^^ -^^ /^ /~^ to form new kinds of plants? /^ \^ \^ ^-X /, — "^J^ — ^\ (6) to reproduce useful plants {^0) 10 reproauce useiui pianis ^^ -^^^ ^^ ^-^ ^-^ y^ (see page 255, Civic Biologij) ? ^P ^P [^ \^ \^ \^ 2. What kind of reproduc- tion is this called, sexual or asexual? Explain your answer in a well- written paragraph. Problem 159 : To deter^mine the working of Mendel's Law. Materials. — Text illustra- £^^^^^£^ Q i tions, charts, material illustrating Mendel's Law. Observations. — Study the il- lustrations very carefully. No- Diagram to Illustratk Mkn^el'8 Law. •^ ' White Dominant, Black Recessive, tice that there are three possi- c'hauacteu. bilitiesof offspring: those having j^ first RcMK^nition; n, second prnora- dominant, recessive, and mixed tion ; c. third gouerutiou. 182 HEREDITY AND VARIATION characters. What will happen if animals or plants having pure dominant characters are bred together? Pure recessive char- acters? Mixed characters? (See chart.) What would be the proportion of dominants, recessives, and mixed offspring in the next generation if breeding continued as in A ? Conclusion. — Why is Mendel's Law of great value to plant and animal breeders? Explain. Problem, 160: To determine some means of bettering, physi- cally and mentally, the human race. Materials. — Charts adapted from Davenport, Goddard, etc. showing heredity of feeble-mindedness, alcoholism, epilepsy, etc. Method. — Careful study of the charts to answer the questions. Observations. — If one of the parties in a marriage is feeble- minded, are any of the children likely to be feeble-minded? If both parties in the marriage are feeble-minded, what is the likeUhood of the children being feeble-minded? ©-xlA] - ^ J^ JL I (S)tIaI E] E] [n I ^^SMS N d. C. d. W]\nj\n]\ A Chart to show the Inheritance of Feeble-mindedness. The Squares Represent Males ; the Circles, Females. A, alcoholic ; F, feeble-minded; N, normal; d.inf., died in infancy. Does alcohol have any effect on the production of feeble-minded children ? Look at the left-hand side of the chart shown above. Does feeble-mindedness there seem to be a dominant or recessive character? Explain. Note to Teacher. — Other problems of a similar nature may be taken up and discussed with seriousness and exceptional interest even in mixed classes. The child is at the receptive age and is emotionally open to the serious lessons here involved. PROBLEM 102 183 Conclusion. — Should foohlo-mindod porsons bo allowed to marry ? Problem IGl : Are ^ood mental parts or quaUticfi cajuOjlc of transmission f row parent to (•Jiild? Materials. — Charts, reference books, etc. Observations. — Study the chart to see if artistic ability may be inherited? Think of any case in your family oi inheritance of some mental trait, such as musical ability. Conclusion. — Are mental traits handed down? Problem 1G2 : Does control of our environment have anyth ing to do with the problem of race betterment? Method. — A study of your own environment. Observations. — Remembering that certain factors of the en- vironment react upon the health and vitality of the people living within that environment and remembering also that certain germ diseases may enter the body through body openings or even through scratches or cuts, then (1) How might dirty streets, stores, and houses affect health in a neighborhood ? (2) How might the milk or water supply affect the health in a given neighborhood? (3) What effect might improper or insufficient food have upon persons within a given locality? (4) How might any of these factors affect the health of mothers with newly born children? (5) Might such factors as mentioned above alfect these babies? If so, how? (6) Knowing what we do about disease germs, should we use public drinking cups? Explain. (7) How might public roller towels be dangerous? (8) What other factors of the environment might work against a healthy race? Explain. Conclusion. - 1. What factors of (he enviromnent have to do with the betterment of tlu^ race? 2. How could you imi)rove your own environment ? 184 HEREDITY AND VARIATION Problem Questions 1. What do we mean by variation? Heredity? 2. Show how these factors work in plant or animal breeding. 3. What is hybridization ? 4. AVho is Luther Burbank and what has he done? 5. Why should farmers select seeds with great care? 6. What part of egg and of sperm cells has to do with heredity? 7. Who was Mendel, and what is his law? 8. What did De Vries do in the problem of heredity? 9. What is meant by eugenics ? 10. What is meant by euthenics? 11. How might alcohol play a part in the problem of heredity? .(See Civic Biology, pages 289-294, 361-372.) 12. What have clean thoughts to do with a clean body? Reference Books Hunter, Civic Biology, Chap. XVII. American Book Company. Hunter, Elements of Biology, pp. 80, 81. American Book Company. Hunter, Essentials of Biology, pp. 81, 83. American Book Company. Allen, Civics and Health. Ginn and Company. Bailey, Plant Breeding. The Macmillan Company. Bailey, Survival of the Unlike. The Macmillan Company. Barr, Mental Defectives. P. Blakiston's Son and Company. Bergen and Caldwell, Practical Botany, Chap. XXIII. Ginn and Company. Bigelow, Sex Instruction as a Phase of Social Education. American Medical Asso- ciation, Chicago. Blatchford, Not Guilty. Albert and Charles Boni. Blood Will Tell. Independent, July 27, 1914. Bulletins and educational pamphlets 1 to 6. Society of Sanitary and Moral Pro- phylaxis. Campbell, Plant Life and Evolution. Henry Holt and Company. Castle, Heredity. D. Appleton and Company. ; Circulars 1-4. Chicago Society of Social Hygiene. ■ Conklin, Heredity and Environment. Princeton University Press. ■ Coulter, Castle, East, Tower, and Davenport, Heredity and Eugenics. University ; of Chicago Press. i Darwin, On the Origin of Species by Natural Selection. D. Appleton and Company. Davenport, Domesticated Animals and Plants. Ginn and Company. Davenport, Heredity in Relation to Eugenics. Henry Holt and Company. Davenport, Principles of Breeding. Ginn and Company. Dawson, Right of the Child to be Well Born. Funk and Wagnalls Company. De Vries, Plant Breeding. Open Court Publishing Company. Duggall, The Jukes. G. P. Putnam's Son^. REFERENCE BOOKS 185 Elliott, Botany of To-day, Chap. XXV. Sccley and Company. London. Ellis, Problem of Race Regeneration, Chap. I. Moffat. Yard and Coini)any. P'oerster, Marriage and the Race. Advanced. F. A. Stokes Company. Forhush, The Coming Generation. D. Appleton and Company. Goddard, The Kallikak Family. The Macmillan Company. Goddard, Feehle-mindcdness. The Macmillan Company. Hall, Adolescence and Psychology. Advancofl. D. .Vppleton and Company. YiaW, J ohyi's Vacations; Chums; The Doctor's Daughter ; Life Problems. American Medical Association, Chicago. Harwood, New Creation in Plant Life. The Macmillan Company. Haynes, Dog Breeding. Outing, March, 1914. Hegner, The Germ Cell Cycle in Animals. The Macmillan Company. Holmes, The Evolution of Animal Intelligence. Henry Holt and Company. Jewett, The Next Generation. Ginn and Company. Johnson, Sexuality in Plants. Science, February 27, 1914. Jordan, The Heredity of Richard Roe. American Unitarian Association. Jordan and Kellog, Scientific Aspect of Luther Burbank's Work. Robertson. Kellicott, The Social Direction of Human Evolution. D. .\ppleton and Com- pany. Kellogg, Darwinism To-day. Henry Holt and Company. Lucas, Animals of the Past. Doubleday, Page and Company. Morgan, The Development of the Frog's Egg. The Macmillan Company. Morley, The Spark of Life. Revell and Company. Morley, Song of Life. McClurg and Company. Mottram, Controlled Natural Selection. Longmans, Green and Company. Plant Breeding, Articles as follows: Webber and Bcssey, Yearbook, Department of Agriculture, for 1899. Hays, Yearbook, Department of .\Kriculture, for 1901. Bailey, World's Work, 1902, p. 1209. Wickson, Sunset Magazine, December, 1901, April, 1902, February, 1903. Harwood, Scribner'a, May, 1904. Garner, Cosmopolitan, July, 1904. Plumb, Types and Breeds of Farm Animals. Ginn and Company. Punnett, Mendelism. The Macmillan Company. Pycraft, Courtship of Animals. Henry Holt and Company. Reik, Safeguarding the Special Senses. F. A. Davis Company. Report of Committee on Matter and Methods of Sex Education. Advanced. American Federation of Sex Hygiene, N. Y. Richards, Euthenics, the Science of Controllable Environment. Whitcomb and Bar- rows. Roosevelt, Twisted Eugenics. Outlook, January 3, 1914. Saleeby, Parenthood and Race Cultxire, MolTat. Yard and Company. Smith, The Three Gifts of Life. Dodd, Mead and Company. Thompson, Heredity. John Murray, London. Torelle, Plant and Animal Children. /f<»r Iheii Grow. D. C. Heath and Com- pany. Wallace, The Geographical Distribution of Animals. Harper :iiid Brothers. Walter, Genetics. The Macmillan Company. Warbasse, Medical Sociology. Advanced. I). .Vppleton and Company. Wasmann, The Problem of Evolution. Paul. Kegan, Trench, TrUlMier and Company, London. 186 HEREDITY AND VARIATION Whethan, The Family and the Nation. Longmans, Green and Company. Wile, Sex Education. Advanced. Duffield and Company. Williams, Every Woman her own Burhank. Good Housekeeping, April, 1914. Williams, With Burhank on the Lawns. Good Housekeeping, September, 1914. Winship, Jukes-Edwards — A Study in Education and Heredity. R. L. Myers and Company. XVIII. THE HUMAN MACHINE AND ITS XEFDS Problem. — To obtain a general uiiderstai} d i n ^ of ihr jtarts and uses of the bodily machine. Laboratory Suggestions Demonstration. — Review to show that the human body is a complex of cells. Laboratory demonstration by means of (a) human skeleton and (/>) manikin to show the position and gross structure of the chief organs of man. To THE Teacher. — As in certain of the previous chapters, the student here takes a preliminary view of the general problem that lasts for the rest of his course in biology, i.e., that of adaptation to function in the human body. A general sur- vey gives an initial interest in problems which are solved later ; it defines the future problems and marks the beginning of some new concepts. Certain structures of the body, as, for example, bones and muscles, are now treated and disniis.sed, not because of their non-importance, but because of the time demanded by the more practical questions relating to dietaries and bodily nutrition. Problem 163: To show that the human body is nuide n]i of cells. Materials. — Scalpel, methyl blue, glass slides, cover glasses, microscope. Method. — Scrape mucous lining; from the moufli. mount on a glass slide, and stain with a drop of dilute metliyl l)lu(\ Cover with cover glass and examine under microscope. Observations. — The large irreguUir bodies with dark blue bodies within them are flat cells {epithelium) from the lining of the mouth. What are these dark blue structtu'es within tlie cell? (The small dots or rods stained deep blue are Imdivin.) Cells from other parts of the body, ghuid, nuiscle. nerve, etc., should be demonstrated luuhM- the compoimd microscope. Conclusion. — What are the units of l)uilding material in the body ? 187 188 THE HUMAN MACHINE Problem 164: To find out some functions of the shin. Materials. — Hand lens, ether or alcohol, large glass jar, two thermometers, model or chart of skin. Method and Observations. — Find out whether all parts of the skin are equally sensitive, by touching with the sharp point of a pencil. Cool a large glass jar, and hold the hand and wrist in the jar for a few moments, closing the opening of the jar with a cloth or a towel. What collects on the inner surface of the jar? What happens when you take violent exercise? Weigh yourself before and after a period of hard work in the gymnasium. Is there any loss in weight? How do you account for it? Place a few drops of ether or alcohol on the back of the hand and note the evaporation of the liquid. What sensation do you feel while the evaporation takes place? Study the model or figure, page 342, Civic Biology. Locate the two layers by means of your textbook. Find and describe the sweat glands, oil glands, and sense organs. Draw a diagrammatic sketch of the model and label all parts. Write a state- ment giving the function of each part. Conclusion. — 1. Is the skin an organ of sensation ? 2. What passes off through the skin? 3. What result to your bodily comfort does this last function have? Problem 165: To study the use of the muscles. Material. — Frogs preserved in formalin. Method. — Remove the skin from the hind leg of a frog. Observations. — Note the " flesh " forming the muscle of the leg. (The wide part or helly of a muscle is attached to the bone by a tough tendon.) Move the leg by pulling the foot up and down. What effect does this have on the muscle? To what are the muscles attached? Muscles of the Left Leg of the Frog. 6, biceps ; g, gastroc- nemius; sm , s e m i - m c m b r a - nosus ; tr, triceps. PROBLEM IGG ISO At how many points are they attached? Exi)lain how move- ment of the leg results from contraction (sliortenin^) of certain of the muscles. What must occur wiien some of the nniscles con- tract? (Look at the position of the muscle on the opjjcj.site side of the leg.) Note the shape of your upper arm. To what is the rounded surface due? Conclusion. — L Why do muscles cause movement? Explain fully. 2. What use, other than movement, have muscles? Problem KiO : To study the structure and uses of the skeleton. Materials. — Prepared human skeleton, manikin. Observations. — Note that the skeleton is divided into two groups of bones : a main framework of the body, the axial skeleton ; and a framework for the appendages, the appendicular skeleton. In life the bones are attached to each other by tough ligaments. Why are the bones jointed? Notice the bones of the head, skull, and face. Knowing that the skull covers part of the delicate nervous system, the brain, what would you say its use was? Note that the backbone, made up of numerous pieces of l)one. has a hole running through it. This hole contains in life the spinal cord. Attached to the vertebrae of the backbone are the ribs. Com- pare the position on the manikin. What is one use of the ribs? Feel your own ribs; bend forward, and take a full breath. What is another function of your ribs? (Remember, to obtain move- ment, muscles must be attached to bones. Why?) Notice that the arm is attached to the main skeleton by means of two bones, the collar bone and the shouldcM' blade. These bones form the pectoral girdle. The leg is in the same way at- tached to a group of strong bones called tlie pelvic girdle. Notice various bones, such as the long arm bone (iiunierus), shoulder blade, pelvic bones, the spines on the ribs, for roughness To THE Teacher. — A demonstration should be shown .it this point to iUu.o- trate the structure of striated and phiin muscU» tissue. Detailed laboratory work on this material is not desirable. 190 THE HUMAN MACHINE where muscles might be attached. In each case seek a place for attachment for the other end of the muscle. Conclusion. — 1. Write a statement giving three general uses of the human skeleton. Take a special bone or bones to illustrate each use. 2. Compare the skeleton with the figure on page 268, Civic Biology. Make a drawing to identify the principal bones. Problem 107: To find the relation of muscles to hones in the human body. Method. — Using the diagrams in your Civic Biology, page 269, work out the different classes of levers. Observations. — In the human body which class of lever is represented when we raise a weight in the hand ? What kind of lever do we use when we rise on the toes? W^hat kind of lever do we use when we nod the head? Conclusion. — 1. Prove that three classes of levers are present in the human body. 2. Find another example of each kind of lever in the human body. Problem, 16 S : To study the joints of the human body. Materials. — Human skeleton. Method. — Study the following joints in the human skeleton: arm at shoulder, knee, head on neck bones, bones of spinal column. Move them in each case. Observations. — • Is the joint hinge-like, ball and socket, gliding, or rotary ? Conclusion. — 1. How many different kinds of joints can you find in a skeleton? 2. What are their specific uses? Problem KiO : To get a preliminary survey of the hiternal structure of the human body. Materials. — Manikin and charts showing organs of the human body. Observations. — If we compare the human body to a machine, then the bones and muscles are the framework. Within the body, PROnLK:\I IGO 191 partially protected ])y the ribs, is a cavity, tho body cnritt/, divided into two uneciual parts by a wall of muscles, the diaphnujm. 'Hie body cavity contains the working parts of the machine : a. The organs of digestion, gidlct, stomach, small intestine, large intestine, the liver and pancreas (two digestive glands), and tho spleen (a gland connected to the digestive organs), b. The organs of respiration, the lungs and tubes which conne(;t them with the outside of the body. c. The organs of circu- lation, the heart and blood vessels. d. The organs of excretion, the kidrieys. e. Most im- portant of all is the nervous system. This con- sists of the brain and spinal cord with the nerves growing out from them, and several different sense organs, which are at the outside of the body and send nerves inward to connect with the central nervous system. Your instructor will demonstrate these to you. We will spend most of the remainder of our course in learning more about the use of these various organs in the human machine. Conclusion. — 1. What are the chief organs of the human body cavity ? 2. Which of these are in the body cavity and which extend into other parts of the body? 3. Which are chiefly outside the body cavity but send branches in? (Get help from j'our instructor or your textbook, page 271, Civic Biology.) 4. Why are sense organs in the skin? How do they send mes- sages to other parts of the body? The Organ's •vnTiiiv THK Human ]i(>DY. Read fuom auove DOWN : t, tongue ; L, larynx ; cp, gullet ; /. lung ; //, heart ; *•/, ster- num ; s.c, spinal cord ;rf, clia|ihragni ; L, livor ; N, stom- ach ; k, kidney ; p, pancreas ; i. small intestine ; /. large int«'stint' ; a. vermi- form iii>pendix: li, bladder ; R, rectum. Problem Questions 1. What is the unit of structure in tho liuninn ])ody? 2. Why do the cells in different parts of the IkhIv differ in siiape and size? 192 THE HUMAN MACHINE 3. Of what use is the skin to man? 4. Would the skin serve the same purposes in the frog as in man ? 5. Name the functions of muscles. 6. How do muscles work? Explain fully. 7. Explain the difference between a voluntary and an involun- tary- muscle. 8. What effect would working of the muscles have upon heat within the body? Explain. 9. What effect might muscular work have upon the skin? 10. Why are the muscles arranged in pairs ? 11. Name three uses of the skeleton. 12. What attaches muscles to bones? 13. What is a lever? Give examples. 14. Show how some one part of the body might illustrate the action of three classes of levers. 15. Of what use are the joints? 16. Explain the difference between a break and a sprain. 17. What is the body cavity? 18. Which sets of organs are found entirely in the body cavity? 19. Which organs are found partially in the body cavity? 20. Why might the nervous system be called the " director of the body"? Reference Books Hunter, Civic Biology, Chap. XVIII. American Book Company. Hunter, Elements of Biology, Chaps. XXXI, XXXII. American Book Company. Hunter, Essentials of Biology, Chap. XXIII. American Book Company. Davison, Human Body and Health (Advanced), Chap. XVII. American Book Company. Goldmark, Fatigue and Efficiency. Charities Publication Committee. Gulick, The Gulick Hygiene Series. Ginn and Company. Gulick, Physical Education by Muscular Exercise. P. Blakiston's Son and Com- pany. Hall, Elementary Anatomy. American Book Company. Halliburton, Kirkes Handbook of Physiology. P. Blakiston's Son and Company. Hammarsten, Textbook of Physiological Chemistry. J. Wylie and Son. Hawk, Practical Physiological Chemistry. P. Blakiston's Son and Company. Hough and Sedgewick, The Human Mechanism, Chap. II. Ginn and Company. Howell, Physiology. W. B. Saunders. Hutchinson, Exercise and Health. Outing Publishing Company. REFERKXCK noOK^ 193 Hutchinson, Athletics and the Heart. Oiitiuy Maoazinv, .]\\\y, 1910. Hutchin.son, Errors in Exercise. Outinu Magazine, April, I'JIU. Overton, General Hygiene. American Book Company. Pusey, Care of the Skin and Hair. D. Appleton and Company. Ritchie, Human Physiology, Chap.s. III-V. World Book Company. Schafer, Textbook of Physiology. The Macmillan Company. Sharpe, Laboratory Manual in Biology, pp. 21S-22o. .American Book Company. Stewart, Manual of Physiology. ^^'. B. Saunders. Stiles, Nutritional Physiology. W. B. Saunders. Verworn, General Physiology. The Macmillan Company. HUNTER LAB. PllOB. 13 XIX. FOODS AND DIETARIES Problems, — A study of foods to determine: (a) Their nutritive value. (b) TJte relation of worh, environment, age, sejc, and digest- ibility of foods to diet. (c) Their relative cheapness. id) The daily Calorie requirement. ie) Food adulteration. (/) The relation of alcohol to the human system. Laboratory Suggestions Laboratory exercise. — Composition of common foods. The series of food charts supplied by the United States Department of Agriculture makes an excellent basis for a laboratory exercise to determine common foods rich in (a) water, (6) starch, (c) sugar, (d) fats or oils, (e) protein, (/) salts, ig) refuse. Demonstration. — Method of using bomb calorimeter. Laboratory and home exercise. — To determine the best individual bal- anced dietary (using standard of Atwater, Chittenden, or Voit) as deter- mined by the use of the 100-Calorie portion. Demonstration. — Tests for some common adulterants. Demonstration. — Effect of alcohol on protein, e.g., white of egg. Demonstration. — Alcohol in some patent medicines. Demonstration. — Patent medicines containing acetanilid. Determi- nation of acetanilid. To THE Teacher. — The practical work in this chapter, although outlined to take not more than two to three weeks, has such possibilities of interest and im- portance that more time may well be spent in its consideration. The working out of an individual or family dietary with an estimate of the cost is an exercise that appeals strongly to the average pupil. Food economy and the balance of a ration are needed topics in every household to-day. The practical correlation of work in biology with that of home economics is found here. It might well be worth while to expand this side of the course with girls so that several weeks be devoted to the practical side of dietetics. Much of 194 PROBLEM 171 195 the laboratory work can be transferred to the hilx)ratory of home economics or to the home. Problem 170: How to deternvine the nutritive value of fond . Materials. — Set of government charts on food values. Tables on pages 276, 278, 279, Civic Biology. NOTE. — Food has two possible vahaes : it may be oxidizofl to release enercy or it may help build tissue. The burning value of foods may ]>c measured by heat units called Calories (a Calorie is the amount of heat needed to raise the tempera- ture of a kilogram of water through one degree centigrade). Remember food is composed of nutrients, water, and refuse. Therefore not all food taken into the body is made use of. Observations. — In the chart on page 27G, Civic Biologij, deter- mine the actual percentage of nutrients in beef, potatoes, oysters, and corn meal. Do all foods have equal nutritive value? From the government charts make a table in which you will place : (a) Ten foods rich in protein (15 per cent or more). (6) Ten foods rich in carbohydrates (50 per cent). (c) Ten foods rich in fat (50 per cent or more). (d) Ten foods having a high fuel value (1500 Calories or more per pound). (e) Ten food substances that are over 50 per cent water. IIow would water affect the cost of food, providing you had to pay for the water? (/) Five foods rich in mineral salts. Conclusion. — In your opinion which of the foods shown are the best tissue-building foods ? The best energy-producing foods ? Explain. Remember that hving matter is made uj) of carbon, oxygen, hydrogen, nitrogen, sulphur, and a minute amount of mineral salts. JProblem 171: The use of the bortih calorimeter. (Optional.) The bomb calorimeter may be demonstrated by the instructor and its mechan- ism explained. Roys should be urged to try to experiment at home with homemade apparatus. An interesting series of home experiments on the burning value of different food sul)stances worked out first hand will do much toward getting indi- vidual interest in the topic. Cirls should ai)proach this entire subject from the side of household economics. Much work can be done in household economics that will be scientifically explained in the biological laboratory, the two subject.s giving und taking much from common ground. 196 FOODS AND DIETARIES The experiments of Atwater with the respiration calorimeter should be explained and pictures of the apparatus shown so that the pupils may be impressed with the delicacy and magnitude of the experiments. This respiration calorimeter is de- scribed by Professor Atwater as follows : "Its main feature is a copper- walled chamber 7 feet long, 4 feet wide, and 6 feet 4 inches high. This is fitted with devices for maintaining and measuring a ventilat- ing current of air, for sampling and analyzing this air, for removing and measuring the heat given off within the chamber, and for passing food and other articles in and out. It is furnished with a folding bed, chair, and table, with scales and appliances for muscular work, and has telephone connection with the outside. Here the sub- ject stays for a period of from three to twelve days, during which time careful analyses and measurements are made of all material which enters the body in the food, and of that which leaves it in the breath and excreta. Record is also kept of the energy given off from the body as heat and muscular work. The difference between the material taken into and that given off from the body is called the bal- ance of matter, and shows whether the body is gaining or losing material. The difference between the energy of the food taken and that of the excreta and the energy given off by the body as heat and muscular work is the balance of energy, and if correctly measured, should equal the energy of the body material gained or lost. With such apparatus it is possible to learn what effect different conditions of nourishment will have on the human body. In one experiment, for instance, the subject might be kept qmte at rest, and in the next do a certain amount of muscular or mental work with the same diet as before, then by comparing the results of the two, the use which the body makes of its food under the different conditions could be determined ; or the diet may be slightly changed in the one experiment, and the effect of this on the balance of matter or energy observed. Such methods and apparatus are very costly in time and money, but the results are proportionately more valuable than those from simpler experiments." The experiments of Chittenden should also be explained. (See Chittenden's Nutrition of Man.) Atwater's Calorimeter. (See diagram on page 197.) Atwater's respiration calorimeter, an apparatus for determining the income and outgo of energy, and respiratory products of the human body, under varying con- ditions, consists of an air-tight copper chamber, insulated from the surrounding air by a zinc casing and three wooden ones, with dead-air spaces between. It is provided with a door and a window for the introduction and removal of food. Closely attached to the outside of the copper wall are 304 thermoelectric couples {A) which, electrically, report the temperature of the calorimeter chamber to the observer's table {B). The temperature of the chamber is maintained as nearly constant as possible by a current of cold water, pumped by the electric pump (C) through the cooling tank (D) to {E), where its temperature is taken just before it enters the large-surface, winged pipes around the chamber. When the water emerges at (F), its temperature is taken again and its volume and flow measured at the water meter {G) before it returns to the pump. From these data, knowing the rise in temperature and the amount of water so raised, the amount of heat developed within the calorimeter may be computed. The flow of water may be regulated so as to carry off any amount of heat developed. PROP.LEM 172 U): In order to assure accurate work on the respiratory i^roduots, the system of ventilation is also a closed one. The vitiated air is drawn out by the pipe (//). and then through a double row of vessels of sulphuric acid (/. /, /, /) to remove water vapor, and vessels of soda lime (./, ./, ./, J) to remove COt, to the electric pump (K). From here it is returned through pipe (L) to (A/), where any deficiency in oxygen is noted and remedied from a tank of that gas before it is pumped through the regulating pans {N, N) into the chamber. Method. — Using the diagram and explanation, try to explain to your own and your teacher's satisfaction the working of the At water calorimeter. Conclusion. — What is the practical value of the ai)paratus? Problem 172: To find tJie value of food as a tissue buildci^ cojnpared with its cost. Method. — Use the tables on pages 198-201 ; make sure you understand the various column headings. Note. — Foods may be considered cheap if they furnish more than .12 n' a pound of protein (the tissue builder) for 10 cents at present prices ; medium prictxl 198 FOODS AND DIETARIES if they furnish from .06 to .12 pound of protein for ten cents; expensive if they furnish less than .06 pound of protein for ten cents. Conclusion. — 1. Pick out ten cheap, ten medium, ten expensive tissue-building foods. 2. In which of the following groups are the cheapest protein foods found : meats, cereals, vegetables, fish, shellfish, dairy prod- ucts, fruits? Note also the most expensive. Prohlem 17'i : To find the value of food as a source of energy compared with its price. Method. — Use the following tables as suggested above. NOTE. — Cheap foods give more than 1500 units of energy for 10 cents at pres- ent prices ; medium priced give between 750 and 1500 units of energy for 10 cents at present prices ; expensive give less than 750 units of energy for 10 cents at present prices. Conclusion. — 1. Find ten cheap fuel- or energy-giving foods, ten medium priced, and ten expensive ones. 2. Can you find ten foods that are cheap both as energy pro- ducers and as tissue builders ? NOTE. — An interesting exercise on economic buying of foods for a family or for individual consumption may be worked out from this table, which has been revised by inserting present-day prices. This is of especial value in connection with work in home economics. Comparative Nutritive Values and Prices of Food Materials ^ Price PER Pound IN Cents Ten Cents will Purchase Protein in lbs. Fat and Carbo. Energy Calories Beef Porterhouse steak Sirloin steak . 32 28 28 22 22 .050 .058 .079 .070 .077 325 370 Round steak (top Chuck steak . round) .... 370 420 Plank steak 510 1 Revised by John W. Teitz of the Department of Biology, De Witt Clinton High School. PROBLEM 173 199 Comparative Nutritive Values and Prices of Food Materials Continued Beef — Continued Porterhouse roast .... Rib roast Bottom round Plate (corned beef) . . . Shank (soup beef) .... Veal Cutlets Loin and rib Leg Breast Neck (stew veal) .... Knuckle or shank (veal broth) Mutton and Lamb Loin Leg Shoulder Neck (stew lamb) .... Pork Ham, fresh Ham, smoked Shoulder, fresh Shoulder, smoked .... Ribs and loins Fat salt pork Bacon Poultry Turkey Chicken Sea Foods Bluefish Cod, fresh Cod, salted Halibut, fresh Halibut, smoked .... Mackerel, fresh Mackerel, salt Salmon, canned Pkice PER POCND IN Cents 30 2o 20 10 12 30 26 25 22 20 15 30 23 20 16 23 23 18 18 24 16 32 24 14 15 16 20 25 12 15 25 Ten Cents will purchabe Protein in lbs. Fat and Carbo. En E HOY Calories .0.54 .().■)() .()S2 .i:w .107 .060 .065 .063 .098 .080 .138 .046 .()()5 .060 .18,3 .067 .062 .067 .078 .056 .012 .042 .052 .058 .072 .112 .110 .072 .07S .00«i .100 .088 :i50 470 300 1200 455 170 270 215 290 255 395 490 390 370 1480 670 730 820 7(>0 ()35 2'295 1265 340 325 ir>o 224 2(X) 240 380 305 688 370 200 FOODS AND DIETARIES Comparative Nutritive Values and Prices of Food Materials — Continued Sea Foods — Continued Clams in shells . . . Lobsters, canned . . Oysters, solids . . . Dairy Products Butter Cheese ...... Eggs * . . Milk, whole . . . . Milk, skimmed . . . Milk, condensed . . Cream Vegetables Beans, green . . . . Beans, baked (canned) Beans, dried . . . . Beets Cabbage Cauliflower , . . . Celery Corn, green . . . . Corn, canned . . . . Onions Parsnips Peas, split Potatoes Potatoes, sweet . . . Pumpkins Squash Tomatoes, canned . Turnips Cereal Products Barley Buckwheat . . . . Corn meal Hominy Oatmeal (in pkgs.) . Price PER Pound IN Cents Ten Cents will Purchase Protein in lbs. Fat and Carbo. Energy Calories 40 .025 79 per peck 45 .041 135 18 .030 130 32 .003 1135 21 .096 940 23 .058 280 4.5 .072 720 3 • .102 565 12 .073 1260 15 .034 1220 4 .102 925 15 .045 400 7 .320 2580 2 .052 840 3 .047 415 3 .036 465 7 .032 250 3 .040 600 15 .028 455 4 .033 515 2 .052 1200 7 .351 2515 2 .090 1555 3.5 .035 1085 4 .013 150 4 .018 265 6 .020 175 1.5 .060 835 7 .121 2355 G .069 2770 4 .230 4138 5 .166 3300 9 .185 2050 PROBLKxM 173 201 Comparative Nutritive Values and Prices of Food Materials — Continued Cereal Products — Continued Oatmeal (in bulk) . Rice Flour, graham . . . Flour, rye Flour, entire wheat Flour, wheat .... Bread, white .... Crackers, soda . . . Miscellaneous Cornstarch Molasses . . Olive oil . . Sugar . . Tapioca . . Lard . . . Sausage . . Fruits Apples . . . Apples, dried . Apricots, dried Bananas Berries . Cherries . . Cranberries . Dates . . . Figs .... Grapes . . . Muskmelons . Oranges Peaches Peaches, canned Pears Pineapple . Prunes . Raisins . Watermelons . Price PER Pound IN Cents G 9 4 4 5 4 G 8 8 6 70 5 9 16 22 2 18 10 8 6 6 5 12 20 4 7 6 5 10 I 10 12. .• ir> 4 Te.n Centh will Pukcuabe Protein in lbs. .278 .089 .170 .275 .285 .154 .134 .060 .021 .010 .047 .096 .(M)7 .015 .(K)S .016 .022 .025 .005 .014 .020 .008 .015 .(K)-l .014 .015 Fat and Curbij. Eneiu;v Calories :W8.5 1815 4170 4<)75 :i;i.'>o 4170 2025 23,S0 1S50 25S0 (i05 3756 18.55 2435 965 700 7:>o 121K) 375 290 575 430 915 715 MO (>4() 3«K) 510 255 735 2(K) 9r>o 1045 150 202 FOODS AND DIETARIES Problem 1 7^ : To find my daily Calorie requirement. Method. — Use the following tables carefully. TABLE 1 Daily Calorie Needs For a child under 2 years 900 Calories For a child from 2 to 5 years 1200 Calories For a child from 6 to 9 years 1500 Calories For a child from 10 to 12 years 1800 Calories For girl from 13 to 14 years (woman, light work, also) . 2100 Calories For boy from 12 to 14, girl from 15 to 16 (man, seden- tary) 2400 Calories For boy from 15 to 16 years (man, light muscular work) 2700 Calories For man (moderately active muscular work) .... 3000 Calories For farmer (busy season) 3200 to 4000 Calories For ditchers, excavators, etc 4000 to 5000 Calories For lumbermen, etc 5000 and more Calories Note. — According to Professor Chittenden, a person doing moderate work should not eat more than /^ of an ounce of protein for each pound of his body weight and enough fuel foods added to bring the total up to between 2500 and 3000 Calories, This is a good general rule to follow. Still another check on your daily needs when doing light work may be obtained by multiplying your body weight by 16.1 Calories. The result will be approximately your daily Calorie requirement. But the body needs more energy when it works hard. The hourly Calorie requirement is shown in the following table. TABLE 2 Hourly Outgo in Heat and Energy from the Human Body as Deter- mined IN the Respiration Calorimeter by the United States Department of Agriculture Average (154 lb.) Calories Resting (asleep) 65 Sitting up (awake) 100 Light exercise 170 Moderate exercise 290 Severe exercise 450 Very severe exercise 600 Observations. — Make very careful observations in tabular form giving the exact Calorie requirement of your own body, us- ing first the age requirement (see Table 1), second the sex require- ment (Table 1), third the occupation requirement by the hourly standard (see Table 2). Use judgment in estimating light exer- PR0BLI<:M 175 203 ciso, moderate exercise, and severe exercise. No })oy or ^irl ifi high school ever does very severe exercise. Li^lit exercise mi^ht be taken to mean walking; to school, moving about the house, etc. Moderate exercise would be setting-uj) thill, walking (not running) upstairs, or any exercise that will cause a slight perspiration. Severe exercise would be carrying heavy bundles, football, tennis, or basket ball during moments of active play. Use considerable care in making your estimate because of the value of this problem to you. Conclusion. — 1. How do age, weight, occupation, and sex affect your daily Calorie requirement? 2. What is your daily Calorie requirement? Problem 17^): To find the ]jro])ortion of protein, fat, and carbohydrate needed in my daily Calorie requirement. Materials. — Tables, etc., in tliis volume and in Hunter's Civic Biology. NOTE. — At least three different investigators have slightly different beliefs as to just what this proportion of protein, fat, and carbohydrate should be; but all agree in one detail, that the proportion of protein food used should be kept low. The following table gives the proportion per 100 Calories as given by At water, Chittenden, and Voit, a German investigator. Atwater Chittenden Voit . . . Cal. from Protein 14 10 25 Cal. from Fat 32 30 20 Cal. from Carbohy- drate 54 m iJ5 Of the three given above, the estimate of Chittenden is usually adopted for this country although some j)eople believe that his proportion of protein is a little low. Foods taken into the body having these proportions of the nutrients constitute a fnilanccd ration or dietary because they provide the body with th(» right proportion for tissue building as well as for fuel food. Observations. — Compare the life you lead with that of a day laborer. Would your needs be the same? 204 FOODS AND DIETARIES Compare your life with that Uved by an Eskimo in the Arctic regions. Would the proportion of the nutrients needed by him be the same as you need? Explain. Conclusion. — 1. Would the same proportion of nutrients be needed in all localities? 2. Are there any other factors that might cause different pro- portions of the nutrients needed by individuals? Problem 170: To obtain my daily dietary witJi the 100 Calorie table of Fisher and to make the necessary corrections in my dietary. Materials. — Dr. Irving Fisher of Yale University has worked out the following tables by means of which a person may easily estimate the number of Calories he receives from any given food. The use of these tables is explained in the laboratory exercise which follows. Table of 100 Calorie Portions ^ Calories ! Wt. of Furnished BY TkT T^ Portion contain- 100 Name of Food ing 100 Food Units Calo- (Approx.) ries (OZ.) Pro- tein Fat Car- bohy- drate Cooked Meats Beef, round, boiled (fat) . Small serving . 1.3 40 60 Beef, round, boiled (lean) Large serving . 2.2 90 10 Beef, round, boiled (med.) Small serving . 1.6 60 40 Beef, 5th rib, roasted . Half serving . .65 12 88 Beef, ribs, boiled . . . Small serving . 1.1 27 73 Chicken, canned . . . One thin slice . .96 23 77 Lamb chops, broiled, av. . One small chop .96 24 76 Lamb, leg, roasted Ord. serving . 1.8 40 60 Mutton, leg, boiled . . Large serving , 1.2 35 65 Pork, ham, boiled (fat) . Small serving . .73 14 86 Pork, ham, roasted (lean) Small serving . 1.2 33 67 Turkey, as purchased. canned Small serving . .99 23 77 Veal, leg, boiled . . . Large serving . 2.4 73 27 ^ These tables are here given by courtesy of The Journal of the American Medical Association, Vol. XLVIII, No. 16. PIIOBLEM 170 205 Table of 100 Calohie Poktions — Continued nT Calohie« I T^ Wt. of FURNUHED BY FORTION CONTAIN- 100 Name of Food ING lOU Food Units (Appkox.) C'alo- HIKH IJ»,^ Car- (o».) 1 rf>- tein Fat bohy- drate Uncooked Meats, Edible Portion Beef, loin, av. (lean) . Ord. servmg 1.8 40 60 Beef, loin, porterhouse steak, av Small steak 1.3 32 68 Beef, loin, sirloin steak, av. Small steak 1.4 31 (J9 Beef, ribs, lean, av. . . Ord. serving 1.8 42 58 Beef, round, lean, av. Ord. serving 9 O .54 46 Beef, tongue, av. . Ord. serving 2.2 47 53 Beef, juice Two sm. cups . 14 78 22 Chickens (broilers), av. . Large serving . 3.2 79 21 Clams, round in shell, av. 12 to 16 . . . 7.4 56 8 36 Cod (whole) Two servings . 4.9 95 5 Goose (young) av. . . . Half serving .88 16 84 Halibut steaks, av. Ord. serving 2.8 61 39 Liver (veal), av. Two sm. servings 2.8 61 39 Lobster (whole), a v. . Two servings . 4.1 78 20 2 Mackerel (Span.), whole. av Ord. serving 2 50 50 Mutton, leg, hind, lean, av. Ord. serving 1.8 41 59 Oyster in shell, av. . . One dozen . . (j.8 49 22 29 Pork, loin, chops, av. Very sm. serving .97 18 82 Pork, ham, lean, av. . Small serving . 1.3 29 71 Pork, bacon, med. fat, av. Small serving . .53 6 94 Salmon (Cal.), av. . . Small serving . 1.5 30 70 Shad, whole, av. . . . Ord. serving 2.1 46 54 Turkey, av Two sm. servings 1.2 29 71 Vegetables Asparagus, av., cooked . Two portions . 7.19 18 63 19 Beans, baked, canned Small side dish 2.()() 21 IS ()! Beans, string, cooked . Five servings . 10.66 15 48 37 Beets, edible portion. cooked Three servings 8.7 23 75 Cabbage, edible portion . Three servings 11 20 8 72 Carrots, cooked . . . Two servings . 5.81 10 31 :^K\ Cauliflower, as purchased 11 23 15 62 Celery, edible portion Two mod. b'chs 19 24 ;> 71 Corn, sweet, cooked . One side dish . 3.5 13 10 i 1 Cucumbers, edible portion Six or seven serv. 20 IS 10 1 2 Egg plant, edible portion 12 17 10 73 206 FOODS AND DIETARIES Table of 100 Calorie Portions — Continued ( [Calories Wt. of Furnished BY XT .« T^-rt..^ — Portion contain- _ _ _ "1 f\f\ I ,' r~. ,r-^ TT-— -. _. 100 Calo- Name of Food iNG lUU rooD Units (Approx.) ries Pro- tein Car- (oz.) Fat bohy- drate Vegetables — Continued Lentils, cooked .... One portion 3.15 27 1 72 Lettuce, edible portion . Two sm. heads 18 25 14 61 Mushrooms, as purchased • ••••• 7.6 31 8 61 Onions, cooked .... Two I'ge servings 8.4 12 40 48 Parsnips, edible portion . One half serv. . 5.3 10 7 83 Peas, green, cooked . . One ser\ang 3 23 27 50 Potatoes, baked . . . One good-sized 3.05 11 1 88 Potatoes, boiled . . . One large-sized 3.62 11 1 88 Potatoes, mashed (creamed) One serving 3.14 10 25 65 Potatoes, chips . . . One half serving .6 4 63 33 Potatoes, sweet, cooked . Half av. potato 1.7 6 9 85 Pumpkins, edible portion 13 15 4 81 Radishes, as purchased . 17 18 3 79 Rhubarb, edible portion . 15 10 27 63 Spinach, cooked . . . Two ord. servings 6.1 15 66 19 Squash, edible portion 7.4 12 10 78 Succotash, canned . . Ord. serving . 3.5 15 9 76 Tomatoes, fresh, as pur- chased Four av. servings 15 15 16 69 Turnips, edible portion . Two I'ge servings 8.7 13 4 83 Fruits (Dried) Apples, as purchased . . 1.2 3 7 90 Apricots, as purchased . 1.24 7 3 90 Dates, edible portion . . Three large . . .99 2 7 91 Figs, edible portion . . One large . . 1.1 5 95 Prunes, edible portion Three large . . 1.14 3 97 Raisins, edible portion . 1 3 9 88 Fruits (Fresh or Cooked) Apples, as purchased . . Two apples . 7.3 3 7 90 Apples, baked .... One serving 3.3 2 5 93 Apples, sauce .... Ord. serving 3.9 2 5 93 Apricots, cooked . . . Large serving . 4.61 6 94 Bananas, edible portion . One large 3.5 5 5 90 Blackberries One serving 5.9 9 16 75 Blueberries One serving 4.6 3 8 89 Cantaloupe .... Half ord. serving 8.6 6 94 PROBLEM 17(i 207 Table of 100 Caloiuk Portiosh — Contimud Name op Food Fruits {Fresh or Vooked) — Continued Cherries, edible portion . Cranberries, as purchased Grapes, as purchased, av. Grapefruit Grape juice Gooseberries .... Lemons Olives, ripe Oranges, as purqhased, av. Oranges, juice .... Peaches, as purchased, av. Peaches, sauce .... Pineapples, edible portion, av Raspberries, red . . Strawberries, av. . . Watermelon, av. . . . PonnON CONTAIN- ING 100 Food I'nits (Approx.) Small dish . Small bunch Half . . . Small glass . About two . About seven One very large Large glass . Three ordinary Ord. serving One large . One serving One serving Two servings Dairy Products Butter . . . Buttermilk . Cheese, Am. pale Cheese, cottage Cheese, cream . Cheese, Swiss Cream Milk condensed, sweetened Milk, condensed, un- sweetened Milk, whole Cakes, Pastry, Puddings, and Desserts Cake, chocolate layer Cake, gingerbread . . . Cake, sponge .... Custard, milk .... 1 pat 1^ glasses 1^ cubic in. 4 cubic in. 1| cubic in. 1^ cubic in. 2 ord. glass. 5 cup . . t cup . . Small glass J ord. sq. piece 2 ord. sq. piece Small piece . Ord. cup Wt. of 100 Calo- KIEH (02.) C\ljOHlF.tt FuilNiaUED BY 4.4 7.5 4.8 7.57 4.2 9.2 7.57 1.31 9.4 ().G2 10 4.78 5.40 8 G.29 9.1 27 .44 9.7 .77 3.12 .82 .8 1.7 1.0() 2.05 4.9 .98 .90 .89 4.29 I'ro- tein 5 3 5 7 9 7 4 4 4 8 10 .5 34 25 76 25 25 5 1(1 24 19 2(3 Fat 10 12 15 4 14 91 3 ') 2 7 G 15 99.5 12 73 8 73 71 8() 23 50 52 22 23 25 5(i Car- bohy- drate 85 85 80 89 \m 95 77 7 91 100 91 94 89 90 92 75 88 54 2 If) 2 1 9 67 26 29 71 71 68 18 208 FOODS AND DIETARIES Table of 100 Calorie Portions — Continued Calories Wt. of Fu RNISHED BY Portion contain- __ _ _. 1 i\f\ T^ ,r^ ,f~^ T T _,^ 100 Name of Food ING 100 l^OOD UNITS Calo- 1 (Approx.) ries Pro- tein 1 Car- (oz.) Fat bohy- drate Cakes, Pastry, Puddings, and Desserts — Continued Custard, tapioca . Two thirds ord. 2.45 9 12 79 Doughnuts . . . Half a doughnut .8 6 45 49 Lady fingers Two to three . .95 10 12 78 Macaroons Two to three . .82 6 33 61 Pie, apple One third piece 1.3 5 32 63 Pie, cream One fourth piece 1.1 5 32 63 Pie, custard One third piece 1.9 9 32 59 Pie, lemon One third piece 1.35 6 36 58 Pie, mince One fourth piece 1.2 8 38 54 Pie, squash One third piece 1.9 lb 42 48 Pudding, apple sago One serving 3.02 6 3 91 Pudding, cream rice Very small serv- ing . . . . 2.65 8 13 79 Pudding, Indian meal HalP ord. serving 2 12 25 63 Pudding, apple tapioca . Small serving . 2.8 1 1 98 Tapioca, cooked Ord. serving . 3.85 1 1 98 Sweets and Pickles Catsup, tomato, av. . . i qt. bottle . . 6 10 3 87 Honey Pour teaspoons 1.05 1 99 Marmalade, orange . . Four teaspoons 1 .5 2.5 97 Molasses, cane .... Four teaspoons 1.2 .5 99.5 Olives, green, edible portion Seven olives 1.1 1 84 15 Pickles, mixed . . 14.6 18 15 67 Sugar, granulated . . . Three teaspoons or 1| lumps . .86 100 Sirup, maple .... Four teaspoons 1.2 100 Nuts, Edible Portion Almonds, av Eight to fifteen .53 13 77 10 Brazil nuts Three ord. size .49 10 86 4 Butternuts About six . . .50 16 82 2 Coconuts .57 4 77 19 Chestnuts, fresh, av. , . i of a cup . . 1.4 10 20 70 Filberts, av Ten nuts .48 9 84 7 Hickory nuts .... About ten . . .47 9 85 6 Peanuts Thirteen, double .62 20 63 17 PROBLEM 170 200 Table of 1(K) Calorie Portionh— Continued Name of Food Nuts, Edible Portion — Con- tinued Pecans, polished Pine nuts (pignolias) . Walnuts, California . Cereals Bread, brown, av. . Bread, corn (johnnycake) av Bread, white, homemade Corn flakes, toasted . Corn meal, ^anular, av Crackers, graham Crackers, oatmeal Hominy, cooked Macaroni, cooked Oatmeal, boiled Popcorn . . . Rice, boiled . Rice, flakes . Rolls, Vienna, av. Shredded wheat Spaghetti, av. . Zwieback . . . Portion contain- ing 100 Food Units (Approx.) Miscellaneous Eggs, hen's, boiled Eggs, hen's, whites Eggs, hen's, yolks . Omelet . . Soup, beef, av. Soup, bean, av Soup, cream of celery Consomme . Clam chowder Chocolate, bitter Cocoa . Ice cream . About eight About eighty About six . Ord. thick slice Small square . Ord. thick sHce Ord. cereal dish Two crackers Two crackers Large serving Ord. serving 1^ serving . Ord. cereal dish Ord. cereal dish One largo roll . One biscuit . One serving Size of thick slice of bread . One large eg^ . Two whites Two yolks . Small serving . 2.} plates . . Very large plate Two phitcs . Five to six cups Two plates . Half a square . J of 5 ff cake Small brick. Wt. op 100 Calo- ries (oz.) Cai.oriks fuh.nihhed by .40 .50 AS Lr> L3 L3 .97 .90 .82 .81 4.2 3.85 5.0 .80 3.1 .94 1.2 .94 .97 .81 2.1 0.4 .94 3.3 13 5.4 0.3 29 8.25 .50 .()9 l.() Pro- tein 22 10 9 12 13 11 10 9 11 11 14 18 11 10 8 12 13 12 9 32 1(H) 17 34 09 20 ir. 85 17 8 17 5 Fat 87 74 S3 10 1 5 20 24 2 15 7 11 1 1 / 4. 1 21 OS (K) 14 10 47 18 72 53 ()2 Car- bohy- drate 7 4 7 84 72 81 88 85 71 05 87 71 /.) 78 89 91 81 82.5 87 70 17 70 37 15 65 20 30 33 HUNTER LAB. PROB. — 14 210 FOODS AND DIETARIES NOTE. — Should you desire to add further items to the prccodiug tabic, obtain Experiment Station Bulletin 28, The Chemical Composition of American Food Materials, by Atwater and Bryant. (Send 10 cents in coin to Superintendent of Documents, Washington, D.C.) The weight in ounces of a standard portion equals 1600 divided by number of Calories per pound given in table. The Calories fur- nished by protein equal the percentage of protein given in the Bulletin table mul- tiplied by 1860 and divided by the number of Calories per pound. The same cal- culation and factor applies to carbohydrates. For fat, calculate the same way, but use the factor 4220 in place of 1860. Verify the three results by adding to see if they equal 100 Calories. Daily Dietary of a First Term High School Boy Calories Protein Fat Carbohy- drate Total Breakfast Orange Hominy (a small serving) . Avitli milk 3 oz. and, . sugar (3 teaspoonfuls) . Toast, 2 slices with butter One boiled Qgg Coffee, cream, and sugar . . 6 8 9 3 .5 32 1 3 1 26 1 66 68 28 91 67 15 100 15 70 Lunch Cream of corn soup . . Soda crackers (3) ... Bread, 2 slices .... Butter, 1 pat 59.5 11 15 26 .4 5 26 193 58 30 12 75 56 358 31 105 162 162 18 610.5 Prunes, 5 large .... Cup of milk custard . . Dinner Boiled mutton .... Two baked potatoes . . Brown gravy .... 83.4 35 22 3 10 .3 15 1 15 231 65 2 68 4 60 66 42 478 176 8 60 19 136 40 153 792.4 Bread (a thin slice) . . Butter Spinach (large serving) Pineapple (canned) . . with juice .... Molasses cookies . . 101.3 307 592 1000.3 Total day's dietary = 2403.2 Cal. PROBLEM 178 211 Method. — First make careful note of all food that enters your body during 24 hours. Not only the amount taken at meals, hut all between meals, should be noted. Usincri- ment Station, Washington, D.C. Eggs and their Uses as Food. Farmers' Bulletin 12S. V. S. Dep.-irtmcnt of Agri- culture, 1906. Fdcis about Milk. Farmers' Bulletin 42, U. S. Department of AKrif .Vgricultun'. 1907. Fisher, Food Values. Bulletin 13, American School of Home Economics, Chicago. 218 FOODS AND DIETARIES Food and Diet in the United States. Yearbook, U. S. Department of Agriculture. Food Value of Fruits. Review of Reviews, September, 1914. Foods, Nutritive Value and Cost. Farmers' Bulletin 23, U. S. Department of Agriculture. Forbes, What Not to Do For a Headache. World's Work, June, 1910. Fruit and its Uses as Food. Yearbook Reprint. Hendrick, Farce of Pure Food Law. McClure's Magazine, August, 1914. Hopkins, Bread from Stones. Country Life, March, 1914. Howard, The Use of the Microscope in Food Adulteration. Separate 455, Yearbook U. S. Department of Agriculture,' 1907. Hunt, The Daily Meals of School Children. Bulletin 3, U. S. Bureau of Education, 1909. Hutchinson, Applied Physiology. Edward Arnold. Influence of Food Preservatives and Artificial Colors on Food. Chemical Bulletin 84, Parts 2, 3, U. S. Department of Agriculture. Johnson, The Drug Clerk a Poor Doctor. World's Work, July, 1910. Journal of Home Economics. American Home Economics Association. Kebler and others, Harmfulness of Headache Mixtures. Farmers' Bulletin 377, U. S. Department of Agriculture. Kellogg, Battle Creek Sanatarium Diet List. Good Health Publishing Company, Battle Creek, Mich. Langworthy, Functions and Uses of Food. Experiment Station Circular 46. Loaf of Bread. Scientific American, April 25, 1914. McGill, Infants' and Invalids' Foods. Bulletin 185, Inland Revenue Department, Ottawa, February, 1910. Medical Fakes and Fakers (pamphlets on) . American Medical Association, Chicago, lU. Milk as Food. Farmers' Bulletin 74, U. S. Department of Agriculture, 1904. Milner, The Cost of Food as Related to its Nutritive Value. Reprint from Yearbook, U. S. Department of Agriculture, 1902. Milner, The Use of Milk as Food. Farmers' Bulletin 363, U. S. Department of Agriculture. Mitchell, A Course in Cereal Foods and their Preparation. Bulletin 200, Agricultural Experiment Station, Washington, D.C. Moore, Oysters and Methods of Oyster Culture. Report U. S. Fish Commission, 1897. Norton, Food and Dietetics. American School of Home Economics, Chicago, 1907. Nostrums and Quackery. American Medical Association, Chicago, III. Patrick, Household Tests for the Detection of Oleomargarine and Renovated Butter. Farmers' Bulletin 131, U. S. Department of Agriculture, 1901. Pope and Carpenter, Essentials of Dietetics. G. P. Putnam and Sons. Protection of Food Products from Injurious Temperatures. Farmers' Bulletin 125, U. S. Department of Agriculture. Purdy, Foods which Make Energy. Delineator, June, 1914. Pure Food Laws. Survey, May 23, 1914. Rensselaer, Food for the Farmers' Family. Cornell University Reading Course, Series III, No. 14, 1905. Retail Prices of Food, 1890-1907. Bulletin 77, U. S. Bureau of Labor, 1908, Washington, D.C, refi:rence j^ooks 219 Rorer, Correct Combinations of Foods. Good Housekeeping, May. 11)1 I. Russell, The Danger in the Drug Store. Pearson's Magazine, June, IIUO. Sinitli, Deleterious Ingredients in Foods, l^cience, February, 1010. Snyder, Human Foods. The Maenullan f 'oinpauy. Sugar as Food. Fanners' Bulletin 9.3, U. S. Department of Aurieulture, I'JUO. Thompson, Diet. Frederick Warne and ('ompany, London. 1*.K)2. Weyl, Pure Milk and Human Life. Success Magazine, March, 1!M)',). Wiley, Foods and their Adulteration. P. Blakiston'.s Son and Company. Williams, Factors of Bread Making. Home Economics, February. 1914. XX. DIGESTION AND ABSORPTION Problems. — To determine where digestion tahes place by ex- amining :— (a) Til e functions of glands. (b) The work done in the mouth. (c) The ivorh done in the stomach. (d) The worh done in the small intestine. (e) The fanction of the liver . To discover the absorbing apparatus and how it is used. Laboratory Suggestions Demonstration of food tube of man (manikin). — Comparison mthfood tube of frog. Drawing (comparative) of food tube and digestive glands of frog and man. Demonstration of simple gland. — (Microscopic preparation.) Home experiment and laboratory demonstration. — ■ The digestion of starch by saliva. Conditions favorable and unfavorable. Demonstration experiment. — The digestion of proteins with artificial gastric juice. Conditions favorable and unfavorable. Demonstration. — An emulsion as seen under the compound microscope. Demonstration. — Emulsification of fats with artificial pancreatic fluid. Digestion of starch and protein with artificial pancreatic fluid. Demonstration of "tripe" to show increase of surface of digestive tube. Laboratory or home exercise. — Make a table showing the changes pro- duced upon food substances by each digestive fluid, the reaction (acid or alkaline) of the fluid, when the fluid acts, and what results from its action. To THE Teacher. — The chief purpose of this chapter is to make plain the chem- ical changes that take place during the process of digestion. The experiments given have been found to be much more useful for immature minds of first-year students than a longer series of conditions, which, although necessary for the fulfillment of the technically correct experiment, are nevertheless extremely confusing to the beginner. We here deliberately sacrifice some of the factors in the experiment in order to maintain interest and obtain understanding. The absorption of foods is a difficult subject even for the adult, so experimental work is not deeply treated. Nor should much more than memory work be ex- pected at this time because of the several factors involved and the extreme diffi- culty of their control. We cannot expect our teachers, much less our pupils, to 220 PROBLEM 184 221 be expert physiological olioniisls. Hut we ean obtain and undorstand some of the data involved. It is with such an end in view that tho rather curtailed li.st« of important happenings in the process are here outlined. Problem 184' To compare the digestive systmyv of a fro^ with that of man. Materials. — Opened frogs preserved in 4 per cent foi inalin, manikin showing digestive tract, opened frogs' stomachs, hand microscopes, charts of digestive systems or cHagrams on jiage 297, Civic Biology. Method and Observations. — Note in the opened specimen of the frog the ghstening membrane {peritoneum) hning the body cavity. It is this membrane in man that becomes inflamed and causes peritonitis. Notice the large, reddish brown organ covering most of the other organs. This is the liver. Count the lobes or divisions of the hver and compare the position and general structure with the liver of man (use manikin). Lift up the middle lobe of the liver and find the gall bladder, a greenish sac. This contains bile, a secre- tion from the liver. Now compare with the manikin to see if you can locate where the bile gets into the food tube. The food tube begins at the mouth, continues as a short wide gullet into the stomach (just under the liver). Compare these structures in the frog with similar structures in man. The stom- ach of the frog leads into a long coiled stiudl intestine and thence into a very short large intestine. What difference is there between the frog and man in this respect ? Note that all the organs are held in place by a fold of the body cavity lining called the mesentery. What might its use be? A pinkish body, the i): To understand the structure of a villus. Method. — Study the figure of the villi on page 307, Civic Biol- ogy; make sure you understand tlie use of each part. Conclusion. — 1. If blood goes into \\\o villus, what change in its composition might take place witliin it? 2. How do fats get into the villi? What becomes of the fats? Problem lf)(i : IIoiv uuty foods be absorbed by the rilli? Observations. — Suppose* the villus is lined with a dclicMlc -kin- like covering. How might li(|ui(l food pass through? Suppose movements of other organs should i)ress upon or s(j:ieezc the 228 DIGESTION AND ABSORPTION intestines. Would any food be forced through? Might- fluids pass through in the same way as a sponge absorbs water? Conclusion. — In what ways is liquid food absorbed? Problem 19 7 : To find the pathway of absorbed foods. Method. — Study the diagram on page 309, Civic Biology; re- member that digested food is within the intestine. Follow the course of sugars and digested proteins as far as the heart. What happens to the blood vessels in the liver? NOTE. — Sugar is taken from the blood and stored as animal starch {glycogen) in the liver and muscles. Fat during the process of digestion by the pancreatic juice is split into fatty acids and glycerin and is absorbed as such. In the villi, these fatty acids and glycerin are rebuilt into small fat particles. They pass through the lymph capillaries, called the lacteals, which empty into the thoracic duct and thence into the heart and circulation. Conclusion. — 1. Write a brief paragraph summarizing the different pathways by which food reaches the heart and general cir- culation. 2. Complete the following table : Food s VT'Kere A"b sorted Torrrv Adoptations PcrtKs to Heart ' 1 Problem Questions 1. What are the uses of (a) the incisors, {h) the canines, (c) the premolars, and {d) the molars? 2. How many teeth are there in our first set of teeth? When do they begin to come, and when do they go? 3. What makes teeth decay? 4. Why should we clean the teeth night and morning? REFERENCE BOOKS 22!) 5. What harm ini«;ht oomo from s\vall()\viMk. 1901. Rexford. One Portion Food Table. Published by author. Rosenau, All about Milk. Metropolitan Life Insurance Company. Rosenau, The Milk Question. Houghton Mifflin Company. Russell, Strength and Diet. Longmans, Green and Company. Sherman, Food Products. The Macmillan Company. Spargo, The Common Sense of the Milk Qucstiort. The Macmillan Company. Stiles, Nutritional Physiology. W. B. Saunders. Taylor, Digestion and Metabolism. Lea and Febiger. The Waste of Overeating. Success Magazine, March, 1910. Thompson, Practical Dietetics. D. Appleton and C^ompany. Vegetables. Experiment Station I^.ulletins 43, GS ; Farmers' Bulletin 250. De- partment of Agriculture, Washington, D.C. Wade, X-ray Pictures of Digestive Tract. Scientific American, May 9, 1914. Wardall and White, A Study of Foods. Giun and Company. XXI. THE BLOOD AND ITS CIRCULATION Problems. — To discover the co7)%}:>osition and uses of the dif- ferent parts of the blood. To find out the vveans by which the blood is circulated about the body. Laboratory Suggestions Demonstration. — Structure of blood, fresh frog's blood and human blood. Drawings. Demonstration. — Clotting of blood. Demonstration. — Use of models to demonstrate that the heart is a force pump. Demonstration. — Capillary circulation in web of frog's foot or tad- pole's tail. Drawing. Home or laboratory exercise. — On relation of exercise on rate of heart- beat. To THE Teacher. — To prove that blood contains liquid food and to show how blood is made are the first considerations in this chapter. The uses of the cor- puscles may well be shown in part by experiment. Proof of circulation of the blood centers around two experiments : e\ddence that the heart is a force pump and the demonstration of capillary circulation in the tadpole's tail. Interesting and vital laboratory work may be done by comparing graphs of the heartbeat of members of the class when at rest, after mental work, and after physical work. Interesting correlations between physiologic age, sex, and rate of heartbeat may also be worked out. The importance of ferments in the blood is a new and fascinating topic to which time should be devoted if materials are available to the teacher. Problem 198 : To prove that blood contains nutrients. Materials. — Ox blood, nitric acid, ammonia, Fehling's solution, formalin, iodine, test tubes, lamp, egg beater. Method. — Collect some blood at a slaughter house. Set aside one bottle to clot (label it clotted blood). Place some of the fresh blood in a flat bowl and beat it with an egg beater. Fill a bottle with the red liquid (label it defibrinated blood). After washing, place the fibrin, or threads which stick to the egg beater, in a third bottle. Pour 4 per cent formalin on the fibrin to 232 PROBLl'.M 1;ives off oxygen) into the second tiihe. Observations. — Note the chanj^e of coloi- in hotli lest tubes. The change from a deep purple to a scarlet occurs in the lun^ as blood passes through them. Conclusion. — 1. How can we know of the presence of oxygen in the blood? Of carbon dioxide? 2. How and when would carbon dioxide get into the blood? (Remember the cells of the body do work.) Note. — The red corpuscles contain a substance known as hcemogluhin which readily unites with oxygen. When the corpuscles take up oxygen, their color changes to a brighter red. 3. How is the oxygen carried in the blood ? Problem 201 : To study the structure of the heart. Materials. — Model of a human heart, beef heart (opened), and charts. Method. — Refer to chart of circulation, page 321, Civic Biology. Find the heart, arteries, and veins connected with it. Find out where the chief arteries lead and from where tlie large veins come. Also examine a beef heart or a good model and note the four chambers, the valves, and the blood tubes leading to and from it. Note. — The upper chambers (see model) are called the rij^ht and left auridis respectively ; the lower chambers the right and left ventricles. Observations. — Which have the thicker walls '^ What is prob- ably the use of these walls ? Notice the position of the valves and the direction of their movement. In what direction do arteries lead? Veins? Into how many chambers is the heart divided? Do these chambers all connect with one another? Can you find a solid wall between the right and left sides? Can you show the heart to be a double force pump? Where does the right side of the heart send the blood? The left? Conclusion. — Write a paragraph describing th(^ structure of the heart. Drawing. — Make a drawing from the model. Liil)el all parts. 236 THE BLOOD AND ITS CIRCULATION Prohlem "202 : To .^tudy the circulation of the hlood. Materials. — Liviiiig tadpole under influence of a 1 per cent solution of chlorotone, mounted on a piece of board having a \ inch hole bored in one end. Place the thin part of the tadpole's tail over the opening ; keep the tadpole moist by wrapping it in wet cotton. (The fin of a living goldfish or the web of a frog's foot may be used.) Observations. — Observe the network of small blood vessels containing moving disks, the corpuscles. In some of the tubes the blood appears to move in spurts. These tubes are arteries and lead from the heart. Trace the tiny arteries in the direction the blood flows and notice they divide into very small tubes called capillaries which connect the arteries with tubes called veins. The latter lead back to the heart. How does a capillary differ from a small artery or a small vein ? Does the blood flow in an artery differ from the flow in a vein? Describe the disk-like bodies (red corpuscles) in the blood. How do they compare in size with the diameter of the capillary tube? Make a copy of the following diagram in colors, labeling all parts, showing blue for veins, purple for capillaries, and red for arteries. Changes in the Blood within the Capillakies. Conclusion. — 1. How does blood get from arteries into the veins ? 2. What change might take place on the way? Why? 3. What causes the pulsation (pulse) in the arteries? PKOHLKM 2().j 2:i: Problem 20S : To deterniiiie tlie rate of your oini hrorthrat. Method. — Take your own pulso by placiii*!; the fourth finder of your right hand on the left wrist, just at the hase of the tluunl) about one inch up on the wrist ; or phice the finj?(T on the side of the head just in front of the ear. After gettinj^ the pulso, wait for a signal, then count the nunib(>r of beats for one minute. Give your age and rate of your pulse per minute to a pupil chosen to place the returns from the class on the ])oard arrangecl ''by age." Classify boys and girls separately. Hctte. Age 60-65 66 70 of P \xl s e. 71-75 76-80 81-85 6(> 90 12,6 13. 13.6 14 etc. Conclusion. — 1. From this table make a grapii tliat will siiow the normal heartbeat of the pupils of your class. 2. Does sex have anything to do with the rate? 3. Does age? Problem 204=: What is the effect of hard mental work nn the pulse heat ? Method. — Under the direction of the teacher do some hard problems in arithmetic for about five minutes. Now count pulse as before and tabulate. Conclusion. — Does mental work affect the heartbeat? Problem 20r> : What effect has e.vereise on the heartbeat ? Method. — Under the threction of a leader, take a hard setiiim- up drill for three minutes with the windows open. Couut the pulse beats as before and tabulate. Also not(^ any difTerence in respiration. 238 THE BLOOD AND ITS CIRCULATION Conclusion. — 1. What effect does exercise have on the rate of the heartbeat? Can you explain the reason? 2. Can you explain the difference in the rate of respiration? 3. Make two graphs superimposed on the original graph (Prob- lem 203), using different colors to indicate the difference between the normal and the other results found in the subsequent experi- ments. Summary of Circulatory System Fill in the following outline. / Summary of Blood water Blood / /serum' digested food Plasmas^ gl^^-^ \ waste products \^ , /red corpuscles Corpuscles<^^j^.^^ corpuscles Matenalg Source. Destination. Constitwervt pcir-t of Bloo flie candles burn ? Remove the lower corks, jlow long do tlic candles burn? Remove one upper and one lower coik fnun one end. How long do the candles burn? Conclusion. — 1. What is the best method of ventilating a room ? 2. Make cross-section sketches and explain the difTerent trials. Use dotted hues and arrows to represent the course of the air. Problem, 215: To study air for preHPncc of dust. (Home Ex- periment.) Materials. — Pan, Petri dish with sterile culture medium. Method. — 1. Sweep a rug vigorously with a dry l)room. Bru.-- - i 10- - 60- - a- - \ »- - : 1 1 S)- - r VI- - B- - i SO- - 20- - 20- - : 10- - 1 C- - ": 0- - 1 0- - i a- - 1 10- - ! 20- - 20- - X- - i JO- - \m\ ^^3 . .^ / J 4? , .. V TIL. 1 JZ^' / i \ \ i iC Sr ' P 1 i i~U ?iii ., ^|i^^ *; sL - ^^si^^S^, m/i'/mmm A Wet and Dry Bulb Thermometer. Conclusion. — What factors cause discomfort in closed rooms where there are many people? Prohlein 218 : To study the structure of the hidney. Material. — A sheep kidney. Method and Observations. — An idea of the internal structure of the kidney of man may be gained by examination of a sheep's PROBLEM 210 247 kidney. Get the butcher to leave the mass of fat around the kid- ney. Of what use might this fat be? Notice, after removing the fat, that the kidney appears to be closely wrapped in a thin coat of connective tissue; this is called the capsule. l{emove the kidney from this capsule. Notice its color and shaiK\ The de- pression called the hilwn is deeper than the corresponding region in the kidney bean. The hollow tube passing out from this region is called the ureter. Blood vessels also enter and leav(^ the kidney at the hilum. Cut the kidney lengthwise into halves. Try to find the following regions: (1) th(^ outer or cortical region; note its color; (2) the inner or medullanj layer; this layer is provided with little projections ; these are the pyramids of Malpighi, so called after their discoverer, Marcello Malpighi, a celebrated Italian physiologist; (3) the cavity or pelvis of the kidney. At the summit of each pyramid is a small opening through which escapes into the pelvis the secretion formed in the little tubules in which the real work of excretion is performed. Conclusion. — 1. Where is the waste taken from the blood in the kidney? (Study the diagram on page 341, Ciric Biology.) 2. Where does this waste pass out of the body? Problem 219: The shin as an or^an of exeretion and heat control. Materials. — Model of human skin in section, tliermometers, hand lens, jars, scales. a. Structure Method. — Examine the model of a cross section of skin. Locate (using your Civic Biology, page 342) the (»i)idermis, dermis, sweat glands, oil glands, nerves, and blood vessels. Observations. — Where is the epidermis and what structures does it contain? Examine the surface of your skin with a hand lens. What structures are found in the dermis? Conclusion. — How might the above-mentioned structures be of value to the body? b. Functions The above question may be answered in part by the following experiments made at home or in the laboratory. 248 RESPIRATION AND EXCRETION 1. Method. — Insert your hand in a clean, dry fruit jar. Wrap a towel over the opening of the jar so as to allow no air to get in between your hand and the sides of the jar. Observations. — What happens in the jar? Conclusion. — What is given off from the hand? 2. Method. — Weigh yourself. Note the weight. Exercise vi- olently for half an hour ; weigh yourself again. Note the weight. Observations. — Was there any change in weight? Conclusion. — How must the change of weight have been brought about and how did the body lose this? Remember that when oxidation of food or tissue takes place in the body three products, at least, are formed : heat, organic wastes, and water. (Food + oxygen = carbon dioxide + water + organic wastes + heat + muscular energy.) 3. Method. — Take the temperature of the body before and after exercise by placing a clinical thermometer in the mouth. Any change? Account for this by the following experiment. 4. Method. — Take two thermometers, place a damp cloth around the bulb of one and leave the other exposed without a damp cloth. After some time, so as to allow the water in the cloth to reach the same temperature as the air in the room, read the two ther- mometers. Observations. — Do they both read the same? How do you account for the difference? Remem- ber that when water evaporates, it takes heat from the air sur- rounding it. Conclusion. — Ap- plying this principle to the skin, explain why evaporation from the skin makes us feel cooler. Income of blood Org'aiv Outgo o/klood to A.1 ll« e.T\.tary Canal 5^ofrorn Small Intestine Ti S S wes Muscle. Nerve . l>oive Li-v er» I< x^ixgs Ki^»\e^.s ^ki IX PUOBLKAI (21:KSTI()XS 2\\) General Conclusion. — Explain Ihc functions of the skin in the light of the above experiments. The skin as an or^an of sensation will 1k> treated later. Fill out the foregoing sunnnary of changes taking place in Lln^d within the organs of the body. Problem Questions 1. How are the lungs fitted to do their work? 2. How is oxygen of use to th(^ body? 3. Show two means by which oxygen is taken into the lungs. 4. Why should we practice deep breathing exercises each day? 5. What habits of bad posture harm the lungs ? Explain ^our answer. 6. What changes take place in the blood within the lungs? 7. What changes take place in air within the lungs? 8. What is given off in the air from the lungs as a result of oxi- dation ? 9. What is oxidation? Where does it take place in the human body? 10. Show exactly how oxygen reaches the cells of the body. 11. What does a cell do as a result of oxidizing food? 12. Why should people sleep with windows open? 13. Make a diagram to show how to ventilate a room. 14. How would you ventilate through a window without making a draft? 15. Can you explain the school system of ventilation'.' Is it a good one? (Remember that hot aii- ris(>s and takes uj) with it carbon dioxide.) 16. Explain the advantage of using damp sawdust when sweep- ing. 17. How would you prevent dust in a sl(M»ping room? In a schoolroom ? 18. Which is cleaner, a paved or an uni):i\e(| f".* Why'.' 19. Why is street sprinkling a g(K)d thing? 20. Which is most cleanlv : n lamp, gas, or el(>ctricit y'.' Why? 250 RESPIRATION AND EXCRETION 21. What are the advantages of the vacuum cleaner over other forms of sweepers? 22. How can you tell when the air of a room becomes bad? 23. Why should considerable water be drunk every day? 24. Of what use is perspiration to the body? 25. How would you keep the skin clean? 26. Give facts to prove that the skin gives off waste products. 27. What is the relation of the heat of the body to work done by the body? 28. What is the physiological use of (a) the cold bath, (6) a moderate bath, and (c) a hot bath? 29. Why do we feel more oppressed on a hot humid day than on a hot dry day? Reference Books Hunter, Civic Biology, Chap. XXII. American Book Company. Hunter, Elements of Biology, Chaps. XXIII, XXIV. American Book Company. Hunter, Essentials of Biology, Chap. XXVII. American Book Company. Baum, Conscious Control of the Diaphragm. Musician, May, 1914. Brady, How He Held His Breath. Technical World, July, 1914. Conditions Inducing Excessive Respiration. Scientific American, July 11, 1914. Davison, Human Body and Health. (Advanced.) American Book Company. Gulick, Hygiene Series, Emergencies, Good Health. Ginn and Company. Hough and Sedgwick, The Human Mechanism. Ginn and Company. Howell, Textbook of Physiology. The Macmillan Company. Long, Physiological Chemistry. P. Blakiston's Son and Company. Macy, General Physiology. American Book Company. Ritchie, Human Physiology. World Book Company. XXIIL BODY CONTROL AND HABIT FOHMATIoX Problems. — How is body control viaiiihiin^fl ? (a) W]iat is tlie niecJiauisDi of dirertioti and control? {h) What is the inetliod of direction and control / (c) Wh at are habits ? How are they formed and Ji otr broken ? (d) What are tJw organs of sense ? What are their uses? (e) How does alcohol affect the nervous system ? Laboratory Suggestions Demonstration. — Sensory motor reactions. Demonstration. — Nervous system. Models and frop: dissections. Demonstration. — Neurones under compound microscope (optional). Demonstration. — Reflex acts are unconscious acts ; show how con- scious acts may become habitual. Home exercise in habit forming. The senses. — Home exercises. — (1) To determine areas most sensitive to touch. (2) To determine or map out hot and cold spots on an area on the wrist. (3) To determine functions of different areas on tongue. Demonstration. — Show how eye defects are tested. Laboratory summary. — The effects of alcohol on the nervous system. To THE Teacher. — The purposes of the followinK e.xerrises are first, to show the pupil that he is dependent upon his organs of sense in order to interpret what goes on about him, thus to get in touch with the factors of his environment ; second, to give him a gUmpse of the great complexity of the mechanism and complicated structure we call the nervous system ; third, to show him liow habit might \yo evolved and the part habit plays in our daily life; and lastly, a slight conception of the workings of the organs of sense, as shown by experimental psychology. Problem 220 : How are we aware of the ivorld aJmiit us ? Materials. — Needle, ether or freezing mixture for local aiuesthe- sia, various substances having distinct taste. Method and Observations. — Touch a flat and a rou^li surface with the finger tips. Prick yourself with a needle. Then place a drop of ether or freezing mixture on the same finger and prick it. Do you still feel? How do you explain the dilTerence? 251 252 BODY CONTROL AND HABIT FORMATION Close your eyes and allow some one to place bits of various substances on your tongue. Can you distinguish between the (hfferent substances? Look at this page. How do you get your knowledge of what is on this page? At how great a distance can you hear a watch tick? Conclusion. — Through what organs do we become aware of the world around us? Problem 2'41 : To determine what parts of the hody are most sensitive to {a) touch, (b) heat and cold. a. Touch Materials. — Compass. Method and Observations. — Blindfold a pupil. Then lightly touch the back of his hand with the two points of a compass. Begin with them close together and gradually move them apart. Have the blindfolded subject tell as soon as the points appear to the touch as two. Experiment further on different parts of the body, and record the results in the form of a table. Place TovccKed. DistanceJjetween Poiivts Bcick of ticLYxd PcxIttv ^ Hccivd I^ixvgei» Tip^ ^A7'^i^i: ULpper' A.x»xxv RctcK o^!Neclk Bcrck - Conclusion, to touch? Which part of the body seemed most sensitive b. Heat and Cold Materials. — Large wire nail, pen, ink, and ruler. Method and Observations. — With a ruler and a pen, draw a square inch on the under side of your wrist. Heat a wire nail so PUOBLEIVI 222 2:).\ it feels very warm. Now lightly touch all parts of the skin within the square area. Do all parts feel the heat, or only the sense of sHght pressure of the nail? Mark witli a little cross all spots that are sensitive to heat. Now cool off the nail by placing it on ice. \\ij)c it diy and a|)j)ly while still cold in the same way to the area marked off on the wrist. Do you feel the sensation of cold in all spots? Mark as before, this time using a dot. Note. — Certain sense cells of the body are sensitive to heat, others to cold. Conclusion. — 1. Do these sense cells occupy the same area? 2. Do all parts of the skin feel heat and cold ? Problem 222 : To study the anatoinij of the nervous si/stem. Materials. — Frogs preserved in formalin, with body cavity opened and viscera removed, scissors, scalpels, forceps, hand lens, charts showing nervous system of man, model of Ijrain of man. Method. — In a frog from which the organs of the body cavity have been removed, note white glistening cords {nerves) which seem to come from under the backl)one. Follow the cour.^e of some of the larger nerves. Where do they lead? Now turn the frog over and with sharp scissors and a scalpel remove very eare- fully the bony covering (the skull) from the whitish body (the brain). Observations. — How many parts do there ai)i)(nir to be in the brain? Notice the white elongated hemisphere of the fore brain or cerebrum. The two anterior projections of the cerebrum are called olfactory lobes. Where do these lobes seem to lead? What do you think, from the name, their use is? Just back of the cerebrum, find two large lobes, known as ()i)tic lobes, which have to do with sight. Look at the chart. Are the eyes connected with the optic lobes? Hack of the optic lobe we find the cerebellu7n and mednlUi, the latiei- ruiming directly into the spinal cord, from which rise the s|)inal nerves you have noted before. Compare, part by part, the brain of the fiog with the model of the brain of man. 254 BODY CONTROL AND HABIT FORMATION Conclusion. — 1. In what respect is the frog's nervous system like that of man? How does it differ? 2. Write a description comparing the nervous system of the frog with your own, using charts and models as a guide. Problem 223 : To study the structure and use of neurons. Method. — Study the figure on page 351, Civic Biology. The cell pictured is known as a neuron or a unit of the nervous system. The brain and spinal cord contain many millions of them. One end of a neuron may be in the brain and the other end far away in the spinal cord ; or one end may be near the surface of the body and the other end in the spinal cord or brain. Observations. — How do these cells compare in length with other cells of the body ? NOTE. — If a neuron has for its function the sending of messages from within outwards (to muscles), it is a motor nerve. If it receives stimuli from without, it ia a sensory nerve. Conclusion. — AVhat structures in the nervous system carry the impulses from the surface to the brain? From the brain to the muscles or other parts of the body? Problem 224 : What is a reflex action ? Method and Observations. — If somebody, without warning, pretends to strike you in the face, what happens? Through . what parts of the nervous system would you become aware of what was happening? With your eyes closed touch a hot surface. What happens? Did you think about withdrawing your hand? Conclusion. — 1. Actions of the sort just described are called reflexes. Explain as well as you can, using the figure, the path- way of a reflex action. 2. Does this pathway reach the cerebrum or thinking part of the brain? Problem, 225 : To compare the reaction time of hearing and touch. Method and Observations. — Let the class form a large circle and then start a whispered word at one end of the circle. Let the ]M^)HLI:M 227 2.j3 teacher note the number of seconds for tlie word to got hack to the startmg point. By dividmjj; this tune hy tlic total niniihcr of participants the average reaction tune for hearing of i\w class can be obtained. Now let members of the class just touch finger tips. In the same manner as in the previous experiment, let the Instructor start a signal (a short pressure of the fingers). (let ihc average reaction time as in the previous experiment. Conclusion. — Which gives a quicker reaction, hearing or touch? Problem 226: To coni/)are a reflex (iHion with an act of tliought. Method. — Using the figures note the pathway with relays of cells between the eye when you see a book, and the rest of the nerves in- volved when you de- termine to pick it up and do so. Observations. — Make a diagram showing the path- way. Compare this pathway with the one taken when you touch your hand against a hot stove in the dark. Conclusion. — What is the chief difference in the nervous path- way between a reflex and an act of thought? Problem 227 ' To study habit forming. Note. — a little chick just hatched in an incubator picks at food. It has no mother to teach it. Such an act i.s called instinctiit:. It is an act arcouiplished without reasoning. When a new-born baby sucks, its act is also instinctive. Upon such instincts life depends. Observations. — When a baby is just learning to walk, tlu^ first step would probably be brought about by its reaching or stretcii- An Involuntary Act. 256 BODY CONTROL AND HABIT FORMATION ing for something it wanted. This would in a way be an instinc- tive act. Can you explain how? When you first learned to write, did you think about making the letters of the words you wrote? Do you now? How do you account for the ease with which you now write? What is the chief difference between the instinctive act of the baby learning to walk and the act of writing? Do we think about writing now ? Did we think about it when we began to learn ? An act consciously repeated many times eventually becomes a hahit. Might a habit be formed through the unconscious repeti- tion of an act? Conclusion. — 1. What is an instinct? 2. What is a habit? How might it be formed? 3. What is the difference between instinct and hal:)it ? Problem 228 : To study the mechanisin of hahit formation. Note. — The formation of a habit involves the simplifying of a complicated process. In an act of thought, e.g., picking up a toothbrush from the washstand (see diagram) the eye sees the brush and relays the message through some sight cells to a nerve center in the back of the brain {O.C^. From there the message is again relayed to (M.C), where the impulse is originated to pick the brush up. This results in a message being sent by another relay of several sets of cells down the spinal cord to the muscles of the arm where the fibers from this neuron end in the muscles. Now if the act becomes habitual, as it does when we brush our teeth each morning, the stimulus caused by the sight of the brush causes a short circuit of the impulse which goes to O.C. and then directly down the spinal cord. The Course taken by the Act of Thought. O.C.^ nerve center; M.C., thought center. Conclusion. — 1. If M.C. is the thought center, then what does habit forming do? 2. Would it be better to make a problem of brushing your teeth each morning or to do it auto- matically (by habit) ? 3. Just how is a habit formed in the nervous center? 4. Of what advantage are habits ? PR0BTJ-:M 2:10 257 Problem 2'iiP : To consider sonir litwiiifiiJ Jidhifs. a. Tobacco Method. — Allow the smoke from half a dozen eiKarettes {o pass through the water of a small jai- eontaiiiing a gcjldlish, or add a small piece of tobacco to the water. Observations. — What is the result? Conclusion. — Might tobacco liavc any similar elTect on other living things, as man? b. Alcohol Method and Observations. — Using the figures given \\\ your Civic Biology, on pages 363, 369, 370, 371, explain why life insur- ance companies consider moderate drinkers an extra risk. Conclusion. — What effect does the drink habit have upon man? Problem 230 : How to go to work to form good habits. Method and Observations. — Study the following statement : " The hell to be endured hereafter, of which theology tells, is no worse than the hell we make for ourselves in this world 1)\- ha- bitually fashioning our characters in the wrong way. Could the young but realize how soon they will become mere bundles of h(d>its, they would give more heed to their conduct while in the plastic state. We are spinning our own fates, good or evil, and never to be undone. Every smallest stroke of virtue or of vice leaves its never-so-little scar. The drunken Rip Van Winkle, in JefTerson's play, excuses himself for every fresh dereliction b}' saying, ' 1 won't count this time.' Well! he may not count it; but it is being counti'd none the less. Down among his nerve cells and fibers the molecules are counting it, registering and. storing it up to be used against him when the next temptation comes. Nothing we ever do is, in strict scientific literalness, wiped out. Of course this has its good >ide as well as its bad one. As we become permanent drunkards by so many separate drinks, so we become saints in the moral, and authorities in the practical and scientific spheres, by so many separate acts and hours of work. Let no youth hare any anxiety about the upshot of his education whatever the line of it nuiy be. If HUNTER LAB. PUGB. 17 258 BODY CONTROL AND HABIT FORMATION he keeps faithfully busy each hour of the working day, he may safely leave the final result to itself. He can with perfect certainty count on waking up some fine morning, to find himself one of the competent ones of his generation, in whatever pursuit he may have singled out." — James, Psychology. Man is thus shown to be a bundle of appetites. Conclusion. — 1. What are the best ways of forming good habits and continuing to observe them? Write a short composition on this important subject. 2. How should one's judgment and appetite relate to each other ? Problem 231 : To determine the relation hetween taste and smell with reference to food flavors. Materials. — Vegetables, spices, flavors. Method. — Close the eyes and hold nose tightly with one hand; with the other place on the tongue pieces of peeled apple, peeled raw potato, peeled raw turnip, and onion. Have the pieces exactly the same taste? Have some one record the results. Are you aware of the different flavors? Are you with the nos- trils open? Experiment with a number of other substances, as sugar, vinegar, va- nilla, mustard, salt, spices, etc., holding nose and closing eyes. Rub the tongue dry. Place a little sugar on it. In what condition must materials be in order to be tasted? Observations. — In tabular form note those substances which are learned by taste only and those which are recognized by taste and smell. Conclusion. — What is the relation of taste and smell in dis- tinguishing flavors? EecogTvized by Taste Kecogrnixed by Smell Apple Onioix Potato Xu rrvlp Salt SxA 0a I- >lnstard Varvilla Virvegar PROBLK.M 2:V.] 250 Problem V/iV ; Ifow to find out cerfnin t/cfcrfs of vision in the laboratory. Materials. — Schnellen's test cards, spoctiiclcs with diopter lenses, clock dial chart. a. Test for Farsightedness Method. — Using the Schnellen's test caids, locate the finest line that can be read at a distance of 20 feci. Test each eye separately, covering the eye not in use with a piece of card hoard. Then place a pah' of spectacles witli a 50 phis diopter lens before the eyes. If as fine or a finer line can now be read, tlien far- sightedness is present and an oculist should ])e consulted, espe- cially if headaches or other symptoms of eye defects are present. Farsightedness is one of the most frequent causes of eyestrain and is hard to detect because the eyesight seems so good. b. Test for Nearsightedness Method. — Use the above-mentioned charts. Determine the finest type you can read at a distance of 20 feet. If it is larger than the 20/20 line, then your vision is defective and you should probably consult an oculist, especially if you have an>- symptoms of eyestrain. c. Test for Astigmatism Method. — Use the clock dial disk at 20 feet. If some lines are blacker than others, then astigmatism is present. If headaches or other symptoms are present, then you should consult an oculist and have glasses fitted to correct this trouble. Next examine a chart or model of tlu^ human eye and deter- mine what defects must occur within yoiu- eye to cause the defects in vision you have found. (Your teacher will I'xplain the terms '' nearsightedness, farsightedness, and astigmatism.") Conclusion. — Have I anv eve defects? If so. what are ihfv, and how nmst I go about to correct them? Problem 23:i : What are some of the efferts of aJrohol on the nervous system ? Method. — Using the figures on pages 'MY.], 305, 300, 30i). :>70. 37 1 . 372, Civic Biology, make a graph to show the elTect of alcohol upon 260 BODY CONTROL AND HABIT FORMATION memory, mental work, ability to do physical work, efficiency, acci- dents. Conclusion. — 1. What effect does alcohol have upon the nervous system ? 2. Write a short composition on this subject. Problem Questions 1. Do you suppose the neurons of a child just learning to walk find it easy to send out exactly the right orders to the muscles? Explain your answer. 2. Do you consciously think about making steps when you now walk? Why not? (Consult chart.) 3. In learning to do anything in concert, how does the first re- hearsal compare with the last ? 4. What is a necessary factor in forming a habit? Remember that pathways become worn along certain lines so that the neurons in those pathways take up the work instinctively. 5. Explain this story: ''A practical joker saw a discharged veteran carrying his dinner home and suddenly called out, ' Atten- tion ' ; whereupon the veteran instantly brought his hands down, dropping his dinner in the gutter." 6. What is the advantage of forming good habits in life? 7. Does habit forming throw work off part of the nervous sys- tem? Explain fully. 8. How are habits formed ? 9. Write a paragraph on the increased effectiveness and power acquired through good habits. 10. Is it easy to break a habit? Explain your answer. 11. Why is a grammar school idler quite likely to continue to be an idler in high school, and a high school idler a college idler ? 12. Why are the railroads requiring their employees to abstain from liquor? Reference Books Hunter, Civic Biology, Chap. XXIII. American Book Company. Hunter, Elements of Biology, Chap. XXXV. American Book Company. Hunter, Essentials of Biology, Chap. XXVIII. American Book Company. Angell, Psychology. Henry Holt and Company. I Berol, System of Memory Training. Funk and Wannalls Coiupany. Brewer, Rural Hygiene. J. H. Lippinoott Company. Brown, Good Health and Long Life, Published by autlior Dr. W. Brown. ('liicnKO. Clouston, Hygiene of the Mind. Unsoundness of Mind. K. P. I)uttf)ii .-in*! Com- pany. Cook, Health through Rational Living. D. C. Cook Puhli.shinj? C'ompany. Dotey, Prevention of Nervous Diseases. D. Applet(jn and Company. Du Bois, Self Control and How to Control H. Funk and Wagnalls Company. Eyestrain from Movie Habit. Literary Digest, May 'M), 1914. Forel, Hygiene of Nerves. G. P. Putnam's Sons. Gordon, Modern Mother. Fenno and Company. Gulick, Mind and Work. Doubleday, Page and Company. Gulick, Control of Mind and Body. Ginn and Company. Gulick, The Will to be Cheerful. World's Work, July, 1908. Hartman, First Book of Health. World Book Company. Hope and Browne, A Manual of School Hygiene. G. P. Putnam's Sons. Hough and Sedgwick, The Human Mechanism. Ginn and Company. Human Being without Cerebral Hemispheres. Scientific American, Decemlxr 13, 1913. Hutchinson, Civilization and Health. Houghton Mifflin Company. James, Psychology, Chap. X. Henry Holt and ComiJany. Johnston, What Science Has Done for the Child. The Designer, March. 1910. Little Danger of Brain Strain. Literary Digest, April 11, 1914. McCabe, Evolution of Mind. A. and C. Black, London. McComb, Alcoholism, Its Causation and Its Arrest. Everybody's Magazine, .\pril, 1909. McComb, Nervousness, A National Menace. Everybody's Magazine, February, 1910. Nervousness. Review of Reviews, January, 1914. Overton, General Hygiene. American Book Company. Partridge, The Nervous Life. Sturgis and Walton. Paton, Nervous and Chemical Regulators of Metabolism. The Macmillan Company. Ritchie, Human Physiology. World Book Compan\-. Roddy, Hygiene. J. A. Roddy, Philadelphia. Rowe, Habit Formation and the Science of Teaching. Longmans. Green and Com- pany. Saleeby, Worry, the Disease of the Age. F. A. Stokes Company. Stiles, Nervous System and its Conservation. W. B. Saunders. Supplemeid to the Brain. Literary Digest, .March 14. 1914. Walton, Why Worry? J. B. Lippincott C«»mi)any. Ward, Problem of Instinct. Independent, ,\uKUst 24. 1914. Worry, Its Cause and Cure. Harper's Bazar, January. 1910. XXIV. MAN'S IMPROVEMENT OF HIS ENVIRON- MENT Problems. — How may we improve our home conditions of living f How may we help improve our conditions at school ? How does the city care for the improvement of our environ- ment ? (a) In inspection of buildings, etc. (b) In inspection of food supplies. (c) In inspection of milk, id) In care of water supplies, (e) In disposal of wastes, if) In care of public health. Laboratory Suggestions Home exercise. — How to ventilate my bedroom. Demonstration. — Effect of use of duster and damp cloth upon bac- teria in schoolroom. Home exercise. — Luncheon dietaries. Home exercise. — Sanitary map of my own block. Demonstration. — The bacterial content of milk of various grades and from different sources. Demonstration. — Bacterial content of distilled water, rain water, tap water, dilute sewage. Laboratory exercise. — Study of board of health tables to plot curves of mortality from certain diseases during certain times of year. Note to Teachers. — The exercises which follow are intended to be suggestive and may be extended indefinitely as time may permit. To make this work of most value, as much collateral reading as can well be made available should be used in addition to the definitely planned home and laboratory work outlined in the following chapter. Field work is of especial importance in this connection as it shows the pupils what the city departments arc doing toward the inspection of factories, care of food supplies, inspection of milk, both in production and in the sale, provision for a safe and ample water supply, disposal of wastes and care of the public health. An effort should be made to have each pupil procure a copy of the 262 PR()BLr:AI 2:35 2fi:i Sanitary Code of the city in which lie lives and then l)y careful study to hco which sections are commonly broken and honored in the hrearh hy the \h>\\vv> or health officials. Concerted action on the part of tlie younyer niend)or« of u conmiunity may bring about decided results for the l)etternjent of a ^iven neinhlxirhood. Thu» our biology courses may become, in truth, courses in rivir f>i»l»uy. Problem 234: How to ventilate nnj bedroom. (Ih.ine Prr»blein.) Note. — This problem varies, depending on llu- nuinl)tT and iM).sitir)n e)f the windows in the room. Remember that air without direct draft i.s what im desired. Method. — Recall the experiment of the candle and the box with the holes in it. (See prol)lem 214.) Wlial hapjx'ned when the corks were removed from the two upper holes on one sid(» only? The two lower holes on one side only? The uj)p(*r and lower holes on one side only? Now apply this principle to the room in which you sleep. Make a diagram to show the air currents in the room when you open the window for ventilation. Is this the best way to have the air currents move? Why? Where should you place the bed and why'.' ShouM yon uso a screen in your room? If so, where should you place it ? Conclusion. — Make a diagram showing the best way to ventilate your bedroom and give your reasons for tliinking this is the best way. Problem 2.3 r> : To C07nj)are the cJitster and the dry clotJi witJi the moist cloth in cleaning the schoolroom . Materials. — Sterile Petri dish with culture inciliuin. broom, oiled rags, oiled sawdust. Method. — Expose a sterile Petri dish cultinc in \\\v schoolroom for two minutes while members of the class tlust with dry cU)tlis and broom. The same day have members of the class clean a neighboring room, having the same conditions of dust and dirt. l)y means of damp cloths and brooms witli damp cloths tied or i)inned over the part that touches the surface of the lloor. Ise damp sawdust on the floor. Expose Petri dish as in above test. Try the experiment in a third room, using oiled rags and oiled sawdust. Expose Petri dish as in test nunib(>r one. 264 MAN'S IMPROVEMENT OF HIS ENVIRONMENT Place the three Petri dishes in a moderately warm and dark place for three days. Then examine. Observations. — In which of the three dishes are the most colonies of bacteria and molds? Continue your observations for about one week's time. Conclusion. — Which of the above methods of dusting a room is the most hygienic and why? (Read Hodge, Nature Study and Life, page 476.) Prohlein 236 : What should I eat for luncheon ? Materials. — Food tables on pages 204 to 209. Method and Observations. — Eight boys in a class eat the following lunches : A brings from home two ham sandwiches, a sponge cake, and an orange. B brings from home two cheese sandwiches and buys a glass of milk and five cents' worth of candy. C buys a hot roast beef sandwich, a cup of cocoa, and an apple. D buys a dish of ice cream, one piece of sponge cake, and five cents' worth of candy. E brings two slices of bread and a square of chocolate and buys a glass of milk. F buys a Frankfurter, a roll, a small helping of sauerkraut, and a glass of lemonade. G buys a plate of vegetable soup, a slice of bread and butter, a cup of tea with milk and sugar, and a piece of apple pie. H buys a helping of beans and a dish of ice cream. Using the tables on pages 204-209, work out the proportion of carbohydrate, fat, and protein contained in each. Add up the total number of Calories in each. Use any standard you wish, Atwater, Chittenden, or Voit. In like manner add your own luncheon to the list. Conclusion. — Which do you think the best balanced? Which the most poorly balanced? Which the cheapest (most nutri- ment for the least money) ? Which the best for a spring or a fall luncheon ? PKOBLEM 237 oOo Problem 2:J7: To make a satiitarij nia/j of m 1/ aivn curinm- ment. Method and Observations.- 1 . xMako a h\Y]n^ map of your immediate neighborhood by diawinn; to scale on cardboard, <.r heavy paper, a map of your home block (if you live in the city) or the neighborhood surrounding your liouse (if you live in a small town). Locate on the map all the houses by oblong shaded areas and use cross hnes to indicate stores. Make an index at the bottom of the map to exphiin the uses of the different stores or buildings shown. Using board of health signs, indicate any homes in which your local board of health has placarded contagious diseases. 2. Locate on the map any standing water, especially water in old tin cans, gutters, or depressed roofs, sewer openings, catch basins, open barrels, or small ponds in vacant lots, ^^'hy should you locate standing water? 3. Find the position of any stables and determine if the heaps of manure are allowed to collect and stand for long periods of time. Why would such manure heaps be a menace to the public health of your neighborhood ? 4. Notice the condition of the garbage pails in your neighl)or- hood. Is garbage collected regularly ? Are all the pails provided with covers? If not, locate coverless pails. Does garbage ever stand for more than two or three days without colhn'tion? Are the garbage pails, after the collection of garbage, washed clean, or is garbage allowed to remain sticking to the sides of the pails from one week to another? What dangers might arise from such pails as the latter? 5. Investigate the condition of all butcher shops, restaurants, or stores where perishable food is exposed for sale. Do you lind the shops screened, and the exposed footl j)rotected from flies? Are there excessive numbers of flies in the ])utcher shops? If .so, then try to locate their breeding |ilaces. Look for bits of stale meat or other refuse that may have been allowed to stand un- touched in a given place for over two weeks. 6. Locate any sewer openings or catch basins from which come bad odors. Also locate any outdoor j)rivies, especially if not 266 MAN'S IMPROVEMENT OF HIS ENVIRONMENT connected with the sewer system of the city. If such toilets are not screened from flies, report the matter at once to your board of health. Why are the latter toilets a particular menace to public health? (See Civic Biology, page 224.) 7. Locate on your map any pushcarts, stands, or stores in which vegetables or fruit are exposed for sale. Indicate if they are obeying the laws of your sanitary code with reference to the ex- posure of goods for sale. Why is it a wise law that requires goods exposed for sale to be covered ? Is there any spitting in the streets in this locality? Are there any other ways in which germs might get in the dust of the street? How might bacteria be carried from the street surface to the food exposed? 8. Find any public fountains having drinking cups ; bubble fountains. Which is more hygienic? Why? 9. Locate any hotels or other places having common roller towels. Why are common towels a danger to public health? What can you do to prevent the use of the public towel in your neighborhood ? 10. Locate any other factors that might in your opinion affect public health in your neighborhood. Factories belching forth smoke or acid fumes, tall buildings shutting out light, old tenement houses, and filthy conditions of street are among such factors. Conclusion. — L Is my neighborhood a good one in which to live? Give reasons. 2. How may I help to better the conditions that affect public health in my locality? Problem 238 : To determine the hacterial content of different grades of milh. Materials. — Different grades of milk, sterile bulb pipette, sterile test tubes, absorbent cotton, sterile Petri dishes containing agar culture media. Method. — Procure milk from different sources and of different grades if in a large city. Be sure to include milk dipped from a can in some store. Have samples of milk collected kept under identical conditions and be sure that the milk has been collected from the milk companies at the same time. Then treat each PROBLEM 2;ilj 207 sample according to the following directions: Willi a .sterile bulb pipette draw off 1 c.c. of milk from a ucU-shaken sample bottle. Add to this 19 c.c. of distilled water, taking care to have the water in a sterile test tube, protected from any dust by an absorbent cotton plug. After mixing the contents of the tulx; thoroughly, quickly flood the surface of a sterile Petri (hsh con- taining agar culture media with the mixture of milk and water. Drain the dish, keeping it covered durin«^ the operation; hibel ; fasten down the cover with strips of paper ; and j)lace to one side. Treat each of the other samples of milk in the same manner as just described, taking care to lalx'l each as to the source of the milk, etc. Place the dishes side by side in a mod- erately warm place. Observations. — After two days, and on each successive day for a week, examine the different Petri dishes. Count the number of colonies in each dish. Also note the different kinds of colonies of bacteria present in each of the Petri dishes. Tabulate the results. Conclusion. — 1. Which of the grades of milk examined sooms to be most free from bacteria ? 2. Should milk be entirely free from l)a('teria? W hat do the bacteria present in greatest quantities probably do to tiie nulk? 3. If several kinds of bacteria are present in milk, what can you say of its purity? What ought to be done with such milk l)efore it is used? Milk 3D 4D 5D Ki «\ei8 in. A. B C D E F Problem ?.?»: To detrrniinr tlir bartrrial ronfnif of soms kinds of water. Materials. — See Problem 238. nmit milk and substitute samples of water. Method. — By means of a sterile l)ull) i)ipette place, m sterile Petri dishes containing agar culture media. v(\\\i\\ amounts of 268 MAX'S IMPROVEMENT OF HIS ENVIRONMENT different waters to be tested. Suggested samples are as follows : distilled water, rain water, bottled spring waters of various kinds, city tap water, standing water from lakes or pools near your home, river water thought to contain sewage, dilute sewage. After inoculating the Petri dishes with the water to be tested, place all Nxn^bei-o/ Colonies i>v e«cK of the dlshes Contain- ing the samples in a moderately warm place. Examine after two or three days, and on suc- cessive days for one week. Tabulate the results. Observations. — In which Petri dishes does the most bacterial growth take place? Conclusion. — 1. Which of the examined samples of water are free from bacteria? 2. Which of the samples are best for drinking purposes? Give reasons for your answer. \A,^citer 3D 4I> 5D A. B C D K F Problem 240 : To determine some of the problems of water supply and sewage disposal for a city. Method. — Visit the sanitation exhibit in a city museum. Observations. — From information gained from maps in the museum, or in some other way, trace the growth of the water supply of your city since its beginning. Where did the city first get its water? What is now the source of the water supply? What impurities are commonly found in water? What do reservoirs do to a water supply ? State several ways in which a water supply becomes contaminated. How might contaminated waters bounding a city affect the health of the citizens of that city? How does the sewage of your city affect the waters surrounding it? How is this contamination brought about? What methods are there for sewage disposal ? Which would you choose for use in your city? Why? How is sewage now disposed of? How do conditions of water supply and sewage disposal on a PK01iLi:M 212 2<;9 farm compare with those in a city? How • of New York New York New York New York New York New York July July Aug. Auk. Sept.'Sopt. Ort. Ort. \ov. N'ov. !).•< I >«•<•. 1911 6,648 1910 7,060 1911 1910 1911 1910 1 1911 I'.dO 78 I'tn 67 l'»lf) 66 1911 52 191U Total deaths, all causes 6,039 6,052 5.361 5,671 71 ■ ! ' t " 63 f ■::■ Typhoid Fever 56 53 88 58 81 62 Malarial Fever 2 3 2 5 5 3 7 3 3 2 2 1 Smallpox .... 1 2 Measles .... '76 60 ii 38 is 28 n ".» if) 19 33 21 Scarlet Fever . . . 40 39 11 11 11 16 7 12 i.'j 24 34 45 Whooping Cougli 46 46 49 41 35 21 30 17 8 1 18 15 22 Diphtheria and Croup 80 116 76 92 49 55 78 1 76 84 112 100 108 Influenza .... 2 5 1 3 5 1 10 7 16 14 21 76 Asiatic Cholera . Cholera Nostras . 46 36 32 25 24 27 Other Epidemic Dis- eases 35 39 43 44 658 674 658 666 673 662 24 26 Tuberculosis, Pulm . 650 728 693 665 711 743 Tub., Meningitis . 82 77 67 54 58 61 '60 '58 49 55 46 53 Other Forms of Tuber- culosis .... 50 57 55 48 38 48 32 43 42 37 64 42 Cancer, ^Malignant Tumor .... 315 291 345 316 328 319 376 323 337 308 337 308 Simple Meningitis 35 52 53 41 36 45 39 48 31 1 36 28 60 Of which Cerebro-Spinal Men- ingitis .... 18 23 22 19 19 21 14 25 13 15 9 29 Apoplexy, and Soften- ing of Brain . . 105 66 54 44 62 74 63 89 75 87 108 102 Organic Heart Dis- eases 596 460 525 391 529 463 629 503 706 6as 768 S28 Acute Bronchitis 40 45 32 48 36 60 59 52 87 84 115 109 Chronic Bronchitis . 8 27 15 11 14 14 15 18 22 35 27 66 Pneumonia (exc. Bron- cho Pneumonia) . 215 199 152 176 165 197 280 309 365 430 543 835 Broncho Pneumonia 251 286 245 241 238 288 288 287 348 332 429 529 Other Respiratory Diseases 60 55 42 47 30 64 48 41 55 65 58 85 Diseases of the Stomach (Cancer excepted) . . . 41 25 35 41 38 40 45 51 38 35 37 61 Diarrheal Diseases (under 5 years) 807 1632 1034 1175 701 791 408 572 174 231 168 165 Appendicitis and Typhlitis. . . . 77 80 69 58 55 39 31 59 41 36 60 58 Hernia, Intestinal Ob- struction . . . 47 53 46 58 41 46 31 43 52 41 45 60 Cirrhosis of Liver 73 74 93 102 95 100 102 76 114 so KM) 122 Bright's Disease and Nephritis . . . 379 414 335 412 326 380 363 388 410 469 449 558 Diseases of Women (not Cancer) . . 32 35 24 24 11 22 32 28 29 28 11 27 Puerperal Septicaemia 17 11 25 20 20 13 10 9 17 ! 13 1 20 ! 16 Other Puerperal Dis- 1 eases 36 49 43 36 32 37 34 34 36 32 i.'i M Congenital Debility I 1 and Malformations 314 319 332 360 313 351 318 370 316 ! 292 an? 1 :<90 Old Age .... 51 46 24 50 28 39 40 32 29 (\:\ Violent Deaths , . 939 534 361 331 323 284 293 308 300 aio a. Sunstroke . . 535 11.-) 17 12 1 9 • • . . • * • • . b . Other Accidents 379 389 322 28(5 301 253 268 290 270 28- _ "■ i 2rv:< c. Homicide . . 25 30 22 33 21 22 25 is .;i 1 19 M 19 Suicide 57 85 50 59 43 67 63 64 .'.s M 72 57 All Other Causes . . 941 886 883 836 804 838 844 807 961 971 921 «m;« Ill-defined Causes 93 1 1 113 96 116 89 89 »5, 72 37 , 24 s 21 272 MAN'S IMPROVEMENT OF HIS ENVIRONMENT Conclusion. — What is the annual cost of typhoid, tuberculosis, and diarrheal diseases of children to the city of New York ? Problem 243 : What are the chief causes of death in a city ? Method and Observations. — From the foregoing table deter- mine : (1) The relation of the number of deaths from infectious dis- eases to the total death rate. (2) The diseases which kill the most children. (3) The per cent who actually die of old age. Conclusion. — 1. What percentage of all people of the city die from old age? 2. What diseases kill most babies and children under five years of age ? 3. What diseases in the list might be influenced by alcohol? Problem 244 : To study the relation of the death rate to the season. Method. — Study tables carefully in the following manner : Note a given disease, as typhoid, and make a graph, using figures given, to determine the number of cases reported and number of deaths monthly in New York city. Conclusion. — Is typhoid equally prevalent all the year round ? How do you account for its great prevalence in the fall? (The instructor should divide up the work so that each member of the class will be responsible for a separate graph. A general discussion may then be held on the relation of various diseases to the city death rate. For example : What disease is responsible for the greatest death rate ?) Problem 245 : To find a relation between flies and mortality. Method. — Refer to mortality tables published on pages 270, 271, and fill in the table on the opposite page. Observations. — With the aid of the given data, construct a graph showing the prevalence of flies and number of deaths per month for the dates given. (In making curves on cross section paper let 1 cm. = 50 deaths, and 1 cm. = 200 flies.) Conclusion. — 1. Is there any relation between the prevalence of flies and the number of deaths from diarrhea? PROBLEM 210 273 Date Jan. Feb. March April May June 250 Jdlt 1900 Aug. 2200 Sept. 200 Oct. Nov. Dtc. Diarrheals under five .... Average . . . Prevalence of flies 40U U 1 1" 2. What factors increase the death of babies during the .sunmicr months ? 3. How would you fight these unfavorable factors? Problem 246 : To determine the numhrr of srliool cJtihlmi who needed treatment for different diseases in .Vew York city, 1914-1915. Method. — Examine the following table carefully. Estimate the percentage of pupils needing attention; the nuinl^er having defective teeth, vision, hearing, and enlarged tonsils. Conclusion. — 1. Would any of the difficulties stated in tlio table interfere with studies? Name and give reason. 2. How would you improve scholarship conditions in the New York city schools ? Physical Examination of School Children, 1014-1915, in New York City Total Number of children examined . . Defects found : Malnutrition Heart troubles Pulmonary disease Defective vision Defective hearing Obstructed nasal breathing . . Defective teeth Enlarged tonsils Orthopedic defects Nervous diseases General defects hunter lab. prob. — 18 :i()5.(")l)5 1().;m() 4.121 5()'J 25,5:n l.STO 'J«>.()r.7 11 ).").:>!>:) :vi.:i7s 1.7J«> 1 .s,s7 S().«')()7 Percentaqe KM) 274 MAN'S IMPROVEMEKT OF HIS ENVIRONMENT Prohletn 247 : How to discover tlie presence of adenoids. Method. — A good medical authority has given the following symptoms as indicating the presence of adenoids, growths in the nose and throat which prevent a sufficient air supply from reaching the tissues of the body : 1. Inability to breathe through the nose. 2. A chronically running nose, accompanied by frequent nose- bleeds and a cough to clear the throat. 3. Stuffy speech and delayed learning to talk. ' Common ' is pronounced ' cobbed ' ; ' nose/ ' doze ' ; and ' song/ ' sogg.' 4. A narrow upper jaw and irregular crowding of the teeth. 5. Deafness. 6. Nervousness. 7. Inflamed eyes. Observations. — Observe members of your own family. Conclusion. — 1. Do any of the family appear to have adenoids ? What makes you believe this? 2. What ought people suffering with adenoids to do? Problem 248 : To find some ways of preventing the spread of disease. Note. — Remembering that disease germs must come from the bodies of those who are sick and that such germs are spread usually by means of material from the mouth, food tube, or other openings where germs could escape, our problem be- comes threefold. The three parts of the main problem are : first, the destruction of such germs as escape from the bodies of the sick ; second, the prevention of such germs as escape from entering the body of well people ; and third, the problem of how to make the body safe or immune from the attacks of such germs as do get into the body of a well person. a. How to kill Germs that escape from the Bodies of those who are Sick Method and Observations. — Using your Civic Biology and such other books of reference as you have access to, answer the follow- ing questions: Take some specific disease, as typhoid fever, tuberculosis, or diphtheria. From what part of the body do the disease-causing germs escape ? PR()BLI':M 248 275 Having dotenniiKHl (his point, ik-m apply what you have learned about disinfectants to the particuhii- (hs( asr you are trying; to prevent the spread of from one person to another. i{cnienilx?r contact with the germ is necessary in order for the well ixjrson to take the disease. In the case of tuberculosis what methods would you advocate for receiving and destroying the material from the mouth (sputum) containing the disease germs? Conclusion. — How would you destroy the disea.se germs in a given disease such as tuberculosis, typhoid, or diphtheria? b. How to prevent the Germs of those Sick from Reaching those in Neighboring Families who are Well. Quarantine Method and Observations. — Notice the manner in which your local board of health treats families in which infectious disea,se has come. Note. — This isolation of the patient is called quarantine. Quarantine may l)c done in the home or by removing the sick jxTson to a hospital wlnrf only that particular disease is treated. Why should persons ill with a germ disea.se be i.solated until they are well? What methods have the board of healtli for warn- ing strangers of the presence of the disease in a home? Why is this necessary? What should be done with heavy rugs, curtains, etc. in the room where one is ill with a germ disease? Why? How could the germs that might lodge in such hangings be kilhMl"' Suggest methods. What do we mean by disinfection'.' Look up your local board of health rules on disinfection and note what is used and how used. (See page 390, Civic Biology.) Wliat should be done to the body, clothing, and hair of a person who has Ikhmi ill with a germ disease before he is allowed to go among well persons again ? Why is this necessary? Would a person lu selfish who neglected such precautions? (^dve reasons. Conclusion. — 1. What is the reason for cjuarantine and l>v what should it be followed to be effective ? 2. Why is there a quarantine station at the entrance of New York harbor? Why is it of particular value there? 276 MAN^S IMPROVEMENT OF HIS ENVIRONMENT c. How to keep Germs from Entering the Body of a Well Person Method and Observations. — Notice conditions existing in crowded cities with reference to the number of flies and the relative number of screens over food exposed for sale, etc. Note the con- dition of the streets and sidewalks, locate saloons or other places where spittoons are found. Find any other places where you think germs might exist and from which they might be carried by flies or other insects. What household insects might be disease carriers ? (See Civic Biology, pages 225-227.) Do you find any public drinking fountains? Any common towels? Common combs and brushes? Also inquire into the condition of your local water supply. Is it pure at the source? Does the supply come from a river? If so, are there any towns or hamlets that empty their sewage into it ? What danger might come from this ? Is your city doing anything to eUminate this danger ? What might your city do to prevent it ? What can you do to prevent disease from this source ? What is the condition of your milk supply ? Does your board of health do anything to protect the milk supply ? If so, then what does it do? Are several grades of milk sold? Is dipped milk sold ? If so, for what purposes ? How can you protect yourself ? What is the condition of the disposal of sewage in your city? Does the sewage reach a river near by untreated, or is the sewage treated before it escapes? Look up some book of reference in this chapter on sewage disposal, and make a report to the class on some of the methods of sewage disposal. Visit a municipal museum, if possible, and report on various methods of sewage disposal as shown in the sanitation exhibit there. Conclusion. — Write up a short composition for your notebook, showing afl the public and private means that should be taken to prevent germs from entering the body of a well person. d. How to develop Immunity in the Body of a Well Person Method and Observations. — Read in your Civic Biology and other reference books as to what immunity is and how it is brought about. PR()IMJ:M 219 277 Note. — immunity is usually meant when the Ixwiy (irvdfjps certain HubHtfincca in the blood known as antibodies. These substanceM seem to give to the Inxly the power to r(>sist the work of genns that entir it. Natural immunity is only po»»il)lf when the bodily condition is good. Of what use to the body in this respect would Ix' {.^ood food, rest, sleep, and moderate exercise? Take each factor separately in your discussion. What might the colorless corpuscles do to help in tliis gaining of immunity ? Note. — Artificial immunity to certain disea.ses is brousht alxjut in the lx>dy l)y the introduction of antitoxins into the body. These sorfs for u statement of the preparation and distribution of this antitoxin. Do you know of any diseases that are fought succe.«^sfully by antitoxins? (Read Civic Biology, pages 300-303.) What great names are connected with the antitoxin treat ukmU of disease? (See Civic Biology, pages 391, 402, etc.) How are antitoxins ad- ministered? Why in this manner? Look uj) tlic .subject of vaccination in Civic Biology, pages 157 and 301. Who discovered this method of treatment of disease? To wliat disea.ses is it applied? Are there any other artificial means of developing immunity in the human body ? Conclusion. — Write a short composition discussing all the ways of developing immunity in the human body. General Conclusion. — 1. What are the functions of the board of health in any city? 2. How may I cooperate with them in their work for the com- mon welfare? 3. How may I develop immunity? Problem 249 : First aid in. tJie Iwmr. ,4 siutimary nf ivluit to do and how to do it. Thf: FiHftT-Aii) 1:mi:iigency Mkdicink Chkst Every family should iia\f the following materials in fix- medieino cabinet out of rcdcli of young children : Alcohol, small bottle. 278 MAN'S IMPROVEMENT OF HIS ENVIRONMENT Aromatic spirits of ammonia, rubber stoppered, small bottle. Carbolated vaseline, small bottle. Castor oil, large bottle. Boracic acid, one ounce. Collodion, in bottle with small brush (use for small cuts). Chlorate of potash tablets. Mustard, powdered, two ounces. Oil of cloves, small bottle (label poison). Seidlitz powders, small box. Soda mint tablets, small bottle. Spirits of camphor, small bottle. Sirup of ginger, small bottle. Sirup of ipecac, small bottle. Subnitrate of bismuth, five-grain tablets, small bottle. Tincture of iodine, small bottle. The following articles should also be kept, either in the case or in an emergency kit : Adhesive tape, small roll. Absorbent cotton, small package. Antiseptic gauze, small package. Clinical thermometer. Bottle of peroxide or 4 per cent carbolic solution. Knife, sharp and used for this purpose only. Scissors. Paper of pins, safety and common. Tooth plasters, small package. The above-mentioned articles ought to be sufficient to make unnecessary the presence of a doctor except in serious cases of illness. How to use the Materials in the Medicine Chest Method. — Use. any good pamphlets or books on first aid. The small pamphlet known as First Aid in the Home, printed and dis- tributed free of charge by the Metropolitan Life Insurance Com- pany, may be used as a text. The uses of most, if not all, of the household remedies are there described. PROBLKAI (^UICSTIOXS 279 Try to answer the f()ll()\vin«i; practical (lucstions on first aid : 1. What would you do to prevent bleedinj; fnjni a cut from wliich blood issued in jets or spurts? 2. What would you do in case of convulsions? 3. How would you treat jioisonin^ in its first stages? 4. If you knew what the substance was that a person had absorbed or taken as a poison, what would you then ijo? Hive three or four different instances, taking common j)()isons in each case. 5. What would you do in a case of fainting? Drowning? 6. How would you treat a case of sunstroke ? Heat exhaustion ? 7. What would 3^ou do in the case of a l)urn ? 8. How would you treat a bad sprain ? 9. How would you go to work to treat a person who has fallen and fractured his arm or leg ? 10. How would you treat a cut from a rusty or dirty metal instrument ? 11. How would you treat a cold? A case of indigestion? Sick headache? Summer complaint? Conclusion. — Are you prepared to meet an emergency re- quiring first aid ? Problem Questions 1. What home conditions do you personally have control over? How would you go about to improve them? 2. What school conditions might you control? What would you do to improve them ? 3. What methods of ventilation are best lor a schoolroom and why? Illustrate with diagrams. 4. How would you ventilate your IxMlroom so a.s to insure fresh air but no draft on the bed'.' I'se a diagram to explain your answer. 5. Why is sunlight important for every bedroom? 6. '' We spend one third of (Mir life in our bedroom. Why not have it cozy and well hlled with fuiiiiture. hangings, and rue???" Criticize this statement from the hygienic standpoint. 7. Why is a damp cloth the b(>st means of dusting a bedroom ? 280 MAN'S IMPROVEMENT OF HIS ENVIRONMENT 8. Why, in moving into a new apartment, should the tenant insist on complete renovation ? 9. What method of heating is best and why? Explain fully. 10. Give three rules which will help prevent insect pests in an apartment. 11. Why is illuminating gas a dangerous friend at times? 12. Give three good school luncheon menus and tell why they are good. 13. In what respects is factory inspection biological? 14. Why should foods be regularly inspected in a city? 15. How is our city milk supply safeguarded? (See your Sanitary Code.) 16. Show three ways in which a city may protect its water supply. 17. To what extent might a filter attached to a faucet be useful ? Why would it not be likely to be effective against germs? 18. Why is typhoid fever considered a country rather than a city disease? 19. What is the work of the department of street cleaning? How can you help in this work? 20. What is immunity ? 21. What is the theory underlying the practice of vaccination? How does this treatment differ from the antitoxin treatment for diphtheria ? 22. What is the method of vaccination for typhoid? Has this method proved of value ? 23. How may you cooperate with the department of health in your city? Reference Books Hunter, Civic Biology, Chap. XXIV. American Book Company. Hunter, Elements of Biology, pp. 317-428. American Book Company. Hunter, Essentials of Biology, Chap. XXIX. American Book Company. Allen, Civics and Health. Ginn and Company. Allen, The Man of Perfect Health. World's Work, July, 1909. Andrews, The White Peril. "White Peril Company, Danbury, Conn. Annual Report of Department of Health, City of New York (and other cities). A War on Consumption. Metropolitan Life Insurance Company. Banks, The Problems of Youth. Funk and Wagnalls Company. Barry, Hygiene of the Schoolroom. Silver, Burdett and Company. REFERENCE BOOKS 281 Bashoro, Ouflines of Practical Sanitation. John Wiley and Sons. Bell, Our Teeth, How to Take Care <>/ Them. Voium American PuMishujK ( 'oinpany. Bjorkman, What Health is Worth to Us. Worl/Tti Wurk, March. 1*.»(K<. Bosworth, Taking Cold. C. S. Davis, Detroit. Brown, Health in Home and Town. D. C'. Heath and Company. Bryce, Laws of Life and Health. ,). B. Lippincott Company. Bulletins and Publications of Committee of One Hundred on National Health. Burbank, Training of the Human Plant. Century Conii>;iny. Burton-Fanning, Open Air Treatment of Pulmvnary Tulirrculosis. I'aul Ji. HoIUt. Carrington, Directions for Living and Sleeping in the Open Air. Metroixjlitan Life Insurance Company. Cavanagh, Care of the Body. E. P, Dutton and Company. Chapin, Municipal Sanitation in the United States. Snow and Farnham. Chapin, Sources and Modes of Infection. John Wiley and Sons. Chappell, The House Fly — Man Killer. Pearson's Mngazinr, .lurn', 1910. Clarke, Vital Economy, or How to Conserve your Strength. We.ssels and BisscU Company. Coleman, The People's Health. The Macmillan Company. Conklin, Heredity and Environment. Princeton l^niversity Press. Conn, Practical Dairy Bacteriology. Oranfxe JucUl Company. Creelman, Is Typhoid to be conquered at Last .' Pearson's Magazine, Decern lx?r, 1909. Curtis, Nature and Health. Henry Holt and Company. Ditmar, Home Hygiene and Prevention of Disease. Duffield and Company. Doane, Insects and Disease. Henry Holt and Company. Dock, Hygiene and Morality. G. P. Putnam's Sons. Dorr, A Fighting Chance for the City Child. Hampton's Magazine, July, 1910. Dorset, Some Common Disinfectants. Farmers' Bulletin 345, U. S. Department of Agriculture, 1908. Dressier, School Hygiene. The Macmillan Company. Du Puy and Brewster, Our Duel with the Rat. McClurc's Magazine, May. 1910. Egbert, A Manual of Hygiene and Sanitation. The Macmillan Company. Fisher, A Departmerd of Dollars vs. A Department of Health. McClurc's Magazine, July, 1910. Fisher, National Vitality. Senate Document No. G7G, Vol. III. COth ConRresi*. Frankland, Bacteria in Daily Life. Longmans, Green and Company. Godfrey, The Health of the City. Houghton Mifflin Company. Goler, Teeth, To7isils, Adenoids. Metropolitan Life Insurance Company. Grinnell, Our Army versus a Bacilltis. National Cieographi<- .Magazine. Gulick, The Efficient Life. Doubleda.\-, Page and Company. Health News. Monthly Bulletin of New York State Department of Health. Hemns, Malaria — Cause and Control. The Macmillan Conip-'my. Home Care of the Sick. Library of Hcmie Economics, Chicago. Horsley and Sturge. Alcohol and the Human Body. Tin- M.icmillan Company. Hough and Sedgwick. The Human Mechanism. Part II. (linn and Company. Howard, The House Fly the Disea.'any. Hutchinson, Common Diseases. Ifandhook of Htnlth. PrcrrnlahJe DiJtctue*. Houghton Mifflin Company. Hutchinson, Sound Bodies for Sound Minds. (!o ■•! and Publir BuildinQM. Longmans, Green ond Company. Tolman, Hygiene for the Worker. American Book Company. Typhoid Fever and How to Prevent it. Metropolitan Life In.snranre Company. YeiWer, Hotising Reform : a Handbook for Practical Use in American Ciiiea. Chari- ties Publishing Company. White, The Occupation and Exercise Cure. Outlook, March. I'UO. Winslow, The Health of the Worker. Metropolitan Life Insurance Company. Woodworth, The Care of the Body. The Macmillan Company. Zinsser, Infection and Resistance. The Macmillan Company. Private Property of Z. p. METCALF No.......... Priv2.te Property of Z. p. METCALF No _ MmM illiipliiiiiih,,. 'iHi!!!;!'!:- PiiSiiiiiiil! (iii '■■\ >'