Tractatum hunc cui titulus The Anatomy of the BRAIN; Dignum Judicamus qui Imprimatur,  


Thomas Burwell, Praeses.  
Samuel Collins, E.  
Fred. Slare, E.  
William Dawes, E.  
Tancred Robinson E.   Dat. ex Aedibus Collegii in Comitiis Censor. Sept. 7. 1694   

THE ANATOMY OF THE BRAIN. Containing its Mechanism and Physiology; Together with some New Discoveries and Corrections OF Ancient and Modern Authors Upon that SUBJECT.  
To which is annexed a particular Account of ANIMAL FUNCTIONS AND Muscular Motion.  
The Whole illustrated with Elegant Sculptures after the life.  
By H. RIDLEY, Coll. Med. Lond. Soc.  
LONDON: Printed for Sam. Smith and Benj. Walford, Printers to the Royal Society, at the Prince's Arms in St. Paul's Churchyard, 1695.   

Spectatissimo Doctissimoque Viro D. D. JOHANNI LAWSON Collegii Regalis Medicorum London. Presidi Dignissimo SOCIIS, Et inter eosspeciatim CENSORIBUS Vel eo nomine Clarissimis 

SAMUELI COLLINS,  
RICHARDO TORLESS,  
EDVARDO TYSON,  
MARTINO LISTER.   NECNON D. D. Electoribus Meritissimis Omnibus & Singulis.  
Tam prae Vniversali Exquisita sua eruditione, quam Artis Apollineae Praxi faelicissima longe Celeberrimis CAETERIS Denique, Egregiis Viris Inclytissimae hujus Societatis ascriptis Paginas has eorum jussu in lucem prodeuntes, Honoris & Obsequii Ergo quam Hamillimè Ossert, H. R.   

THE PREFACE TO THE Reader.  
THAT Reason which, upon first thoughts, seemed of most force to dissuade me from engaging myself upon the Subject I have made choice of in these few following Sheets, (which was, its having been already undertaken by two so eminent Persons, as the late Willis, and the present Vieussenius) upon second became the greatest motives to it. Seeing that even after the best Proofs they have either of them been able to give of Skill or Industry upon this Subject, there hath yet escaped undiscovered both a great deal of the Materials which Nature is wont to furnish for the framing of Parts, and Contrivance too in ranging of them, in order to bring about that great design of making them all contribute their share to the conservation of the whole.  
The truth of this becoming still more evident whilst I became more conversant in Dissection, after some time, put me upon an endeavour, by a deeper Scrutiny, to discover something more than what as yet had come to light: and this I undertook so much the more vigorously, as by how much I reckoned it more preferable to contribute my Mite towards the perfecting of a Work already so happily begun and successfully carried on, than to break the Ice only (the common Fate of the first attempt) of another. With what success I have done it the Reader must be Judge.  
Through the whole description of Parts I have offered nothing but Matter of Fact, and have taken all possible care to avoid being imposed upon myself, by making Experiments in proportion to my Doubts. Some of them have been upon Subjects in their natural, some in their morbid estate, some upon those of Untimely Death; and on those last sometimes whilst the natural Fluids' remained in their proper Vessels, though after a preternatural manner occasioned by Strangulation, sometimes when in the room thereof, other Bodies have been introduced by Injection, as Tinged Wax and Mercury, the first of which by its consistence chief, the other by its permanent nature and colour, contribute mightily towards bringing to view the most minute ramifications of Vessels, and secretest recesses of Nature.  
By this various disposition of the Subject it is that so great Difficulties are overcome in search after Truth, many things appearing oftentimes very plain in one state, which either lay concealed, or seemed otherwise modified in any of the other.  
The Figures were delineated by the hand of that Complete Anatomist Mr. Cowper the Surgeon, whose great Skill in Dissection renders that Talon so fortunate both to himself and his Friends: and how exactly that Work is performed, I submit to the Severest Censure of any who will be at the pains to compare any of the Cuts to the life.  
What I have said upon the Physiologia, in relation to Nutrition and Muscular Motion, depends on Microscopical Observations; and as to the Postulatum on which they both depend, though at first sight it may appear surprising, yet I am confident it will become far less so to those who have been acquainted with what hath been said of the Vascular Compages of Plants by Malpighius and Grew, and of several other Subjects by Lewenhoeck.  
And to conclude, I must confess I have been the better satisfied with it myself, since I met with some Passages in the Works of those learned Micrographists Dr. Power, and of Mr. Hooke, relating to this Subject, in which last, the medium made use of for solution of that famous Phaenomenon of that Plants contraction at the first appulse of Touch from external Objects, as well as the manner of its acting, is the same with that made use of here as a Postulatum, upon which the whole of what is said about Muscular Motion is built: Although at the same time I am sensible 'tis not so applied in that place by the aforesaid Author, whose opinion in reference to Muscular Motion (being the same with that of Dr. Mayow already taken notice of in the following Sheets) is expressly otherwise in the account lie gives of those natural Hygrometers the Beards of Wild Oats, of all the sorts of Cranes Bills and Cats Guts, conformable to the manner of Nature's acting on which, in order to make them proper Indices of the various Changes of Wether (viz, by wreathing and unwreathing) he supposes that to be of Muscular Motion.  
I have quoted Authors, not out of ostentation, but both for their Truth and Errors, to the end that at the same time we may see it reasonable and convenient to read all they say, we may be rendered cautious how we believe; and to put us in mind, that as we sinned something done to our hands by those who have gone before, there is reason we should do something for those who are to come after.   

THE INTRODUCTION.  
HOwsoever the Controversy may stand amongst Learned Men, about the Method and Order which Nature makes use of in the framing the different Parts of Animals, especially as to precedency of Time, some of them supposing a rudimentary delineation, or pre-existence of the whole, which, at the Ingenious Bruner hath rightly observed, must necessarily imply an actual existence of the whole Race of Mankind at once, either in the Testicle or Ovarium of Eve, according to the Learned Harvey, Malpighius, Swammardam, etc. or in that of Adam, according to Lewenhoeck, Dr. Garden, and several others, and consequently must needs also infer an extinction of the same Progeny, as soon as the number of those humane Germens or Animalcles shall be exhausted; others a gradual formation of parts, one after another, by an intestine motion begun and carried on from the time of coition, by the subtle matter in the Cicatricula of the Egg: I see m reason to make myself a Party on either side at this time, seeing the fineness of structure and dignity of functions are sufficient to give preference to one above another, and to render it more worthy of a particular consideration. And this part I take to be the Brain, the delicacy of whose structure is such, that with no little resemblance to its divine Author, whilst it gives us the greatest and clearest discoveries of other things, lies most concealed itself.  
And seeing all that Mystic Knowledge, which in ancient times, in the eyes especially of the Vulgar, appeared mere Necromancy or Witchcraft, as well as all the Curious Discoveries of more modern Ages upon the whole subject of Nature, now going under the more familiar and proper term of Refined Sense, or Philosophy, hath been merely owing to a more accurate knowledge of the parts and modification of Matter, I see not any more likely way of conquering the difficulties yet behind upon any particular subject, than the endeavouring after a further and more nice scrutiny into it by such means and experiments as serve to bring its most minute parts and texture under the test of Sense, which so assisted, doth the same office to the discerning faculty at good artificial Glasses do to it, bringing the Object and Judgement to such a nearness, that even the first Link of the Chain becomes discernible, and the mechanical proceed of Nature so highly instructive to the Understanding, in its finding out and assigning proper Causes to Effects much more obvious and intelligible.  
I shall therefore treat this Noble Part after the aforesaid manner, with all the Justice I can, leaving those invisible, and almost divine things called Animal Spirits, to be treated of more at large, by those more illuminated Philosophers, who see best when their Eyes are put, and content myself with making an inquiry into, and giving a description of whatsoever upon this Subject, by Dissection, shall offer itself as an Object of our Senses.   

THE ANATOMY OF THE BRAIN.  

CHAP. 1. Of the Anatomy of the Brain.  
THE topmost part or Olla of the Cranium being removed, the first part of the Brain that comes in view is the Dura Mater, which, with the subjacent Pia Mater, is accounted only an improper part of the Brain, strictly so called, however of great use in many respects to it.  
'Tis by Spigelius and other Anatomists reckoned, and I think not undeservedly, the thickest and hardest Membrane of the whole Body, enclosing the whole Brain, properly so called, somewhat loosely, sticking almost inseparably to the Basis of the Cranium, and to the top and sides, under the Coronal, Sagittal, and Lamdocid Sutures, very fast by the Sinus' whose description will come in another place.  
In some places of the upper part of the Cranium, which on each side of the Sagittal Suture or Vertex are called Ossa Bregmatis, it adheres not to the Bone, notwithstanding the positive Opinion of Van Roonhuyse, 
Roonh. p. 149.  in his Leiter to Du Foy, to the contrary, who for that very reason would fain take away in a great measure the use of the Trepan and Trefoyne, and altogether the use of the Instrument called Decussorium, which skilful Surgeons do often make use of to make room for the discharge of subsided matter below the fractured place in many Accidents of the Brain.  
'Tis very discernably double, as Columbus and several others formerly, 
Col. p. 348  and Vieussenius lately, have observed, having very strong and large Fibres on the inside, but very small, 
Vienss. p. 3.  and hardly visible, on that side next the Skull; as appeared to me, after having first let it lie a little time in bolling or at least very scalding Water.  
But as to the distribution of the double sort of Fibres on each side this Membrane, I could not by any means find them agreeing with the description Vieussenius hath given of them, as running in an obliqne semicircular manner, externally from before backwards, and in the same figure internally from behind forwards; but far otherwise, on the inside, where they are very strong, they seem manifestly to have three originals from the top part of the Processus Falcatus, before, behind, and in its middle; those before running in a curved manner backwards, half the length, and a great width of the Dura Mater, and those behind running after the same manner forwardly with this difference, that a great number of them bend soon after their rise from that process in a kind of a semilunary way to it again a little on this side the rise of the middle Series of Fibres, others of them making a bigger arch after having stretched themselves wider upon the Dura Mater, bend back again to, and terminate in the Falx a little beyond the rise of the aforesaid middle Series of Fibres.  
Those from the middle part of the Falx run backwardly, but less curved than the rest, terminating as the Fibres which arise backwardly do, at some distance from the Process in the inward Superficies of the Dura Mater.  
As to those belonging to the exernal side or second Lamina of the Dura Mater, they are extreme small and obscure, running from behind forwards.  
Besides these, there are no less remarkable ones belonging to the Falx itself, of two sorts of Orders, the one running straight about half the length of it, on its upper part, from before backwards, the other transverse, from the inferior or fifth Sinus to the superior or third, on the hinder part of the Process, and are most conspicuous there, as the other are towards its foremost part.  
As to the Use of those Fibres, it may be remembered that this Membrane consists of two Lamina's, between which the Veins which reduce the Blood from the Arteries, which furnish the whole Brain with it, run for some space after the manner of the Ureters in the Bladder, in large Trunks, before they enter the Sinus; so that the Fibrous Constitution of this Membrane here, where the Blood-vessels are largest (together with the curved entrance of them into the Sinus, especially in an erect position of the Body) do the office of Valves, support the weight, and promote the ascent of the Blood. But that which is most considerable, is this, That if the inward Lamina of this part, which makes the inferior and lateral part of the Sinus, was not in some measure furnished with additional strength on this side suitable to that which it hath on the other, by reason of its cohesion to the Skull, the Blood which is continually running through it with no small rapidity, especially in great plenitude of the Vessels or preternatural Ebulitions, would frequently burst out, or at least cause such distentions as could not but be very injurious to a part so very tightly sensible; yet notwithstanding, tho' Nature seems plainly to have made a double provision against such Accidents, by the transverse Ligaments within the Sinus, and these strong and numerous Fibres without, I have rarely opened any strangled Body, where some such Rupture, or at least Distension, hath not happened.  
This Membrane hath plenty of Nerves from the foremost Branch of the fifth Pair, and is thereby made very sensible, so that from any molestation given it by the ill Crasis or undue motion of the Blood, it becomes accordingly affected. And as the various distribution of Fibres before described serve in a natural estate to give a kind of springiness to the Vessels, whose Coats are extended by the Blood as they run between the Laminae of this Membrane, to the end the same may be the more readily circulated through them; so in a preternatural estate, no doubt, they are subject to Spasms, which may retard the course of the Blood in such sort, that in some kind of violent Headaches, where the Membrane is affected through overfulness of Blood, and particularly in those which are wont to proceed from Vapours (so called) or Convulsive Motions of Nervous parts, we often observe a fixed ruddiness in the Face, attended with a kind of stiffness and soreness in the Eyes, proceeding doubtless from a stagnation in some measure of the Humours in those parts, through the too slow passage of them into the reductory Vessels or Sinus'. And to this preternatural affection of the Sinus' may certainly many other ill Symptoms of the Brain be imputed, and not to any irregular Syslole and Diastole of the Membrane itself, occasioned through any convulsive or paralytical state thereof, as that curious Speculatist Dr. Mayow hath affirmed, 
Mayow. Tr. 4. p. 49.  seeing not any living Dissection hath ever been found to give Authority to any such Hypothesis.  

The First Process of the Dura Mater.  It hath two Processes, the first of which arises from that part of the Os Ethmoeides, called Crista Galli, and is extended from thence backwards, as far as the concourse of the four greater Sinus' commonly called Torcular Herophili, in the figure of a Sickle, whence it hath that denomination of Falx, and by reason of the strict connexion it hath by certain Membranous Fibres with the Cranium in those places which are immediately under the Sutures, and with the Brain itself, by the intervention of the Pia Mater, (to which it is joined both by the intervention of large Blood-vessels, propagated thence to the longitudinal and lateral Sinus', and certain carnous Adnascencies, as it descends down betwixt the two Hemispheres of the Brain, and afterward at its approach to the back of the Corpus Callosum, (over which that Membrance is loosely expanded) both by continuity of its Membranous Substance and Ramifications of Blood-vessels, terminating in the fifth Sinus, at the bottom of the Process, so that in a Diseased Brain I once saw it drawn up the length of an Inch from the said Corpus Callosum, in the exact form of a membranous thin Production, continued to the fifth Sinus running at the bottom of this Process,) it keeps the Brain suspended in such a natural conformation, that it needs not, to that internal part by the Ancients called Fornix, nor that by Vieussenius of late subslituted in the room of it, called Corpus Callosum, for its support.  
Another Use it hath is, partly to defend the Cerebellum from Compression, to which, by its connexion with the Galli Crista, it doth not a little contribute, but chief the two Hemispheres of the Brain from the like Injury from each other, upon its various position in Sleep or otherwise; and therefore is wanting in many other Creatures, as Calves, Sheep, etc. which not only Sleep less, but for the most part in a less injurious posture.  

The Second Process of the Dura Mater.  The second is that which arising so forwardly as from the hindermost Process of the Wedglike Bone, which composes the back and uppermost part only of the Sella Equina; it passes up betwixt the Cerebrum and Cerebellum, all the way adhering to the internal Eminencies of the Ossa Petrosa to the lateral Sinus', by which means not only the Cerebellum immediately, as is commonly observed, but consequently all the Parts from the beginning of the fourth Sinus, or the Glandula Pinealis, to the last Foramen of the Skull, (viz.) the Caudex Medullaris, with its Appendices the Nates and Testes, (which being placed upon the upper part of the Medulla Oblongata, make a sort of an Isthmus betwixt the Cerebrum and Cerebellum) together with the Nerves proceeding out of it, are defended from the injurious pressure of the hinder Limbs of the Brain.   

CHAP. II. Of the Pia Mater.  
THE Second Integument of the Brain, commonly called Pia or Tenuis Mater, by Galen and many others, Choroeides, from its likeness in substance and ramification of Blood-vessels to that Membrane of the Secondines called Chorion, with much more reason than Vesalius, on behalf of the Plexus Choroeides itself advances against it; was by all the Ancients looked upon as its only other Integument, being a very thin and pellucid Membrane, co-extended with the Brain itself, not only in its outward but inward structure too, as likewise through all its Plicatures, Interstices, and Cavities, even over the Corpus Callosum itself, tho' loosely, as hath been already observed, notwithstanding the great Vesalius affirms the contrary: 
Vestal. p. 778. par. 2.  Which Membrane also a chance cut in pareing the top-part of the Brain down to the lateral Ventricles with a Razor, in a Body I lately had, gave me an opportunity of showing as fair in those Ventricles as the largest Membrane of the whole Body, to several who stood by, notwithstanding Molinetti, 
Mol. p. 7●.  who laughs at all that pretend to have found any such thing, affirms the contrary.  
But this is to be enquired for either in recent Bodies, or such who have before death been, through some Diseases, filled with extravasated Serum, as Dropsies, Stoppage of Urine, some sort of Apoplexies, or the like: That way which in want of the other opportunities discovers it best, is the separating the Septum Lucidum near to its rise, which is just from the Fornix, where it arises from its two Roots, near to which place the Medulla of the Brain gins to advance into the Corpora Striata; for from thence for above half way of its passage backward toward the hinder limbs of the Brain, it continues hollow, and, I am apt to think, is but a Duplicature of this part, tho' it may be somewhat medullary, and therefore, by reason of its transparency, hath the Name of Septum Lucidum.  
This Opinion of the Ancients, of its being the only other, and that a single Integument of the Brain, was equally received for Truth by the late two learned and curious Anatomists Willis and Vieussenius, together with all the other modern Writers, except Bidloo and Bohn, both which affirm, 
Bid. Tab. 8 f. 5, g. Bohn p. 333  they have found another distinct membranous Integument of the Brain coming betwixt the other outward Dura, and inward Pia Mater, the one three hours, the other fifteen days after death; and by them both reckoned the original of the second proper Integument of the Spinal Marrow which Tulpius first discovered, 
Tulp. cent. 1 obs. 29. Vienssen. p. 143. par. 2.  and Vieussenius supposes to be a Duplicature of the Pia Mater in that part only.  
Now, that there was a middle Membrane in some parts of the Brain, and particularly at the Basis of the Cerebellum, from whence it's continued down to the Spinal Marrow, constituting the second proper Integument of that part as aforementioned, I had long since-observed; but whether it be another absolute distinct Membrane from that other subjacent one, by the aforesaid Authors properly named the Pia Mater, and common to the Spinal Marrow with the Brain itself, like as is this other second middle one too, or only one and the same Membrane double, as consisting of two Lamina's, may well be doubted of.  
Wherefore, for satisfaction concerning this difficulty, I have lately made the strictest enquiry possible, and that in a subject most likely to afford a decision in such a Controversy, and this was an Human Brain extremely hydropical, where there was no Cavity or Interstice, without abundance of Water extravasated, insomuch that where ever, according to the natural construction of Parts, there was any larger than ordinary duplicature of this Membrane, as there are at the end of the Calamus Scriptorius, betwixt the superincumbent Cerebellum and Medulla Spinalis, in the Isthmus or space betwixt the Cerebrum and Cerebellum, upon the Processes called Nates and Testes, in the depressed part also of the Brain, between the beginning of the Annular Process, and the first appearance or coming out of the Olfactory Nerves, by Vesalius taken notice of and called a Process of the Pia Mater, 
Visal. p. 794  there was found a great deal of Water distending this Duplicature much beyond its natural limits; so that by way of consequence, if these Cavities were only Interstices of two different Membranes distinctly investing the Brain, and not a Duplicature only of one and the same, the Water would then probably have insinuated itself betwixt them, and made them to have appeared far different from what they did, agreeable to what it hath often been found to do in some Dropsies of the Belly, where the Water hath been found so to have divided or parted the double Membrane of that Region called Peritoneum, as to have rendered it capable of containing the quantity of fifteen Gallons of Water, and upon a discharge of the same after death, by cutting the external Lamina of that Membrane, the other inward one being yet (unknown to the Dissecter) left whole, to have imposed upon the Spectators, and those very sagacious ones, so as that at first sight, till after having recollected themselves, 
Job Mei●r. Obs. 52.  and divided the other second Lamina too, they thought the Bowels of this part to have been wanting; but contrary to this Event, in this Subject I found this Membrane entire, and free from any divulsion throughout its whole circumference, excepting the places afore taken notice of. However, supposing the like conformation here in this with the Membranes of the other parts, I attempted to divide it, and did so successfully in many parts of it, but most readily in the beginning of the superficial Plicatures of the cortical part of the Brain, where there are naturally small Interstices, betwixt which many of the Blood-vessels creep into and immerge themselves in the cortical and medullary parts thereof: So that I think there cannot remain any further scruple of its being only a double, and not two distinct Membranes of the Brain.  
Bidloo very truly observes this first or middle Membrane, by him so called, by me only the first, or one Lamina of a double Membrane, to be thinner than the Dura Mater above it, and thicker than the other Membrane or Lamina under it; which last most properly it is that insinuates itself through all the close Plicatures of the Brain, and that, as by frequent inspection I have often observed, not in a continuous, but rather retiform contexture, and so, by such as love hard words, or terms of Art, may be called after the same name of that Membrane investing the crystalline Humour of the Eye, Arachnoeides.  
The Advantages accrueing to the whole through such a disposition of this part, as hath already been observed, are very considerable, inasmuch as that thereby first of all it becomes not only an Integument of enclosure, on behalf of the Brain, and the Blood-vessels belonging to it in general, but of expansion for Strength too, where the peculiar structure of Parts, in such places as were before mentioned, require it.  
As to the first, the Brain is not only kept more warm, close, and compact, and better defended on its depending part from the asperity of the Bone it lies upon, but the Vessels hereby more strongly supported, and itself secured from being broken or torn, whilst between its duplicature they climb up into the Brain, whose delicate tender Fibres must otherwise of necessity have suffered violence by the largeness and pulsation of the Arteries, together with the weight of them, and the other reductory Vessel, from which the Sinus' meet them.  
Nextly, as it is an Integument of Expansion in the places before mentioned, that tender small part the Infundibulum, where it quits the Brain, in order to its passage into the Glandula Pituitaria, by the circumtension of this outward Lamina, is fortified upon any violent Accident from disruption, and the Brain and Medulla Oblongata, in those places where they are only loosely contiguous, are better preserved in their natural due connexion; all which Advantages, inasmuch as they may more reasonably be ascribed to one double Membrane than two single ones, tho' of the like strength when joined fast together, may not unreasonably be thought to argue for the duplicature of this Membrane exclusively, to the introduction of a third or new one.  
Lastly, as to what concerns the Glandes' and Plexus' which Dr. Willis affirms to be scattered all over this Membrane; as to the former, 
Will. p. 26. col. 1.  I could never see them, but I have seen the external Superficies of the cortical part of the Brain, in strangled Bodies, appear glandulous very plainly, through this transparent Integument, which upon bare inspection, without further enquiry, might easily impose upon the less cautious Spectator.  
As to the latter, the Plexus', and distribution of Blood-vessels from them, after a separation of the serous gross part of the Blood in the aforementioned supposed Glandules, (according to that learned person's conjecture) into the substance of the Brain, in order to produce the finer Animal Spirits; I cannot but look upon it altogether conjectural, till such time as not only the Glandes', but their excretory Ducts also, together with the Emunctories where the supposed excrementitious Juice is eliminated, (lymphatic or reductory Glandes' (if they could be found) never having been by Nature designed to any such use) be first discovered.  

Blood-vessels of the Pia Mater.  This Membrane hath Blood-vessels of two sorts.  
Of the first are these properly belonging to the Brain itself, which, as it hath already been observed, it doth as it were conduct through its Duplicature, in their passage allowing them thereby the opportunity of growing extremely fine, after many serpentine twine towards their capillary Extremities, before they are protended into the Brain itself, 
Bid. Tab. 8. f. 5. l. M  and those are chief spread all-along upon the under or second Lamina of this Membrane. 
Ib. l. G.   
The second are those which belong to this part itself, for its own nourishment, and these I found upon diligent inspection, whilst I separated its second Lamina spread plentifully upon the inside of the outermost or first Lamina, and both these you will find very well delineated in the places quoted in Bidloo.  
This Duplicature is also very plainly communicated to all the Nerves both within and without the Cranium, making by its outward Lamina a second Integument under the first from the Dura Mater to the whole ●asciculus of Nerves, and a third by its inward Lamina, which yields an involucrum or covering to each single Fibrilla, which collectively make up the whole Nervous Body itself, through the admirable fineness of which Membrane investing those medullary Fibrils, altogether insensible of themselves, it happens there is such a nimble consent betwixt part and part, and betwixt all and the Brain itself.   

CHAP. III. Of the Vessels belonging to the Brain in general.  
THE Vessels belonging to this part in common with the rest of the Body, though in reality but one continued Canal variously modified, yet, through the diversity of Fluids they contain, go commonly under the denomination of Arteries, Veins, Sinus', and Lymphducts, and not without good reason, perhaps, the Nerves may be in some sense of the same kind too.  
The two first of these may, with relation to their different distribution, be deservedly considered in a twofold respect, either as they belong to the first Integument of the Brain, or the Brain, properly so called, itself.  
The Arteries therefore belonging to this part called Dura Mater, or first Integument, are three fair Branches on each side.  
The first and foremost of which are sent out from the Carotid Artery, whilst it remains in the fourth hole of the Cranium, 
FIG. 2. hh.  and are propagated chief through the foremost part of the bottom of the Dura Mater, as in the Figure delineated, but greatly mistaken by Dr. Willis, 
Willis p. 2. col. 2. wepf. p. 100L par. 2.  perhaps taking it upon trust from Wepfer, equally with himself therein mistaken; who describes it for a small branch of the Carotid Artery, that runs betwixt the two first Lobes of the Brain, which instead of coming out of the Bone of the Forehead, as he would have it, goes into it without lending any branches to this Membrane at all, being truly delineated and described by the aforementioned accurate Vieussenius. 
Vieuss. Tab. 17. dd, bb. p. 32. par. 4. Wepf. p. 101   
And that this Artery was not only mistaken by, but unknown to the aforesaid Wepfer, is plain, seeing he says, that from the very styliform Process, where the Carotid Artery does indeed enter the long Canal, to the place where it perforates the Dura Mater to enter the Brain, there is not one Branch sent out from it; which Error, by injecting with Wax, which keeps longer in, and shows the Vessels much better than small tinged Liquors, had very easily been avoided.  
The second Branch of Arteries ascend into the Dura Mater by the sixth hole of the Cranium, 
FIG. 2. ll.  together with a Branch of the internal Jugular Vein, and are dispersed laterally all over the forepart of this Membrane, as far as the very Sinus Longitudinalis, (which nevertheless it enters not, as there will be occasion to take notice of hereafter) as in the Figure delineated.  
The third Branch of Arteries climb into the Dura Mater by the eighth hole of the Calvaria, together with a small reductory Branch of the Vertebral Vein, 
FIG. 2. kk.  where the lateral Sinus' enter the internal Jugular (which occasioned the Ingenious Highmore erroneously to believe it entered the very lateral Sinus itself) and the eighth pair of Nerves pass out of the Cranium, 
Highmore, p. 206. par. 1.  which passage of this Artery is not hitherto described by any that I know of; neither have I ever seen it figured, 
Vieuss. tab. 1 kk.  but in Vieussenius' first Cut, and there but very faintly.  
It arises from the external Branches of the Vertebral Artery, 
Vieuss. tab. 8. f. i c. Barthol. p. 431. par. ul●.  according to Vieussenius, but Bartholine makes it to be a slip of the Carotid Artery, calling it the lesser Branch thereof; wherein he is mistaken.  

The Veins of the Dura Mater.  As to the Veins, 
Riol. p. 252 par. 2. Will. p. 2. col. 2. par. 6.  Riolane, and after him Willis, seems to say this Membrane hath none; for tho' the latter hath this obscure expression of them, Tam crebris Venarum propaginibus quam Arteriarum nusquam consita est; speaking of the Crassa Meninx, by which we might guests he thought it had some, 
Will. p. 22. col. 1. par. 4.  yet in another place he plainly substitutes the Sinus' for the reductory Vessels, as well on behalf of this Membrane as the Brain itself; as appears plain enough in the Page noted.  
Vieussenius indeed allows Veins to this part, and says, 
Vieuss. p. 31 par. 3.  they all-along accompany the Arteries, and afterward terminate, according to Veslingus, 
Vesling. p. 210. Vieuss. p. 4. par. 2.  in the internal Jugular; yet in another place he says, some of the Venal Branches discharge the Blood into the Sinus Longitudinalis. Which last is a flat contradiction to the place foregoing, inasmuch as in that he says, they accompany the Arteries all-along after the same manner of distribution or ramification; which, if so, who sees not that they must needs grow capillary towards the Sinus, and consequently be uncapable of reducing the Blood into them, all reductory Vessels being always capillary in the place from which, and not to which, they bring that which they contain.  
Now therefore, neither what the one nor the other says can possibly be true; for, as to the former the learned Dr. Willis, if his Assertion was good, it must of necessity follow, that all the Arteries dispersed through this Membrane must terminate in some of the Sinus', otherwise there will want a reductory Vessel; the first of which is contrary to ocular demonstration, the last to common reason.  
As to Vieussenius the latter, besides what hath been already said against him, if what he says in the place aforecited be true, that the Veins of the Dura Mater run concomitantly along with the Arteries, than they must of necessity answer the ends of other Veins throughout the whole Body, in reducing the Blood adduced by the Arteries, unless the Arteries they accompany discharge their Blood into the Sinusses, (which, as hereafter shall be shown, they plainly do not) for otherwise, seeing they both grow capillary in their ascent from the Basis of the Cranium, they must necessarily be both adductory Vessels, than which, by the Laws of Circulation, there can be no greater an Absurdity.  
Wepfer not knowing of these Veins, was forced to think, and consequently to affirm, That the Arteries leave the Dura Mater in their extremities, and terminate in the Pia Mater, and so have their Blood reduced by the Veins there; but this is evidently not so to the Eye of any who heedfully separates this Membrane from the other.  
Before therefore I proceed to the description of the Blood-vessels belonging to the Brain itself, which by the exactness of method I ought to do, I hope it may be pardonable, if I make a short enquiry after the unaccustomed distribution of Blood-vessels Nature hath furnished the Brain in general with, and the Reasons of its procedure therein.  
The Truth then concerning this affair, is, That contrary to what hath hitherto been observed, the Blood-vessels belonging to this part in general, as hath already been observed, are of two sorts, the one belonging to the Brain itself, the other to its outmost Integuments.  
Now, as to the first, 'tis observable, that the Veins enter not the Brain, nor run concomitantly, like as in other parts of the Body, with the Arteries, (the carotid entering at the fourth hole in the Basis of the Skull, and the internal Jugular at the eighth; the Vertebral Artery at the last and largest hole of the Skull, and the Vertebral Vein at the ninth (which Vieussenius mistakenly calls the tenth) through which it runs into the internal Jugular, 
Vie●ssen. p. 163. par. 3.  at that Veins entrance into the round hole at the bottom of the Skull, under the Styliform Process, where the Sinus Lateralis meets it) where after having advanced into certain venous productions called Sinus', they descend from thence in large Trunks, growing capillary all-along in their passage till they meet the Extremities of the Arteries, and are indeed no other than mere Branches of the Sinus', and consequently I look upon the Sinus' themselves no other than large Veins.  
The common reason all modern Authors give for this different distribution of Blood-vessels belonging to the Brain, from the other parts of the Body, is, that it may receive an equal warmth at the top as at the bottom, as being thereby very much assisted in the production of Animal Spirits in an equal proportion all over; and that it is so may very well be granted: but, that Nature had yet another provident Intention, will be as evident, if we consider, that if the Veins had ascended with the Arteries through the holes in the bottom of the Cranium, upon all great Ebulitions of the Blood, the pulsation of the Arteries would in that Stricture of the Vessels made by the Bone, of necessity hinder the freedom of its return by the Veins, and consequently occasion a stagnation of Blood through the whole Brain, to the utter subversion of all its faculties, nothing being more certain, than that upon any considerable abatement of circulation there presently happens by way of restagnation, a secession of the watery and thin from the more gross and red part of the Blood.  
The other way of the Veins entering the Brain (viz. those appertaining to its outward Integument, one at the sixth hole of the Basis of the Cranium, the other at the eighth, as aforesaid) is, their ascent with the Arteries after a quite different manner from the former, even to their capillary Extremities; a manifest indication that they serve for the reduction of so much Blood from the Dura Mater as the aforesaid sort of Vessels, the Arteries, have brought thither; and although by reason of their smallness Nature seems not to have been so solicitous in avoiding the Inconvenience supposed to have followed, upon the Artery's entering the same hole with the Veins, taken notice of in the preceding Case, where they are very large, and consequently the Effect might prove much more injurious, yet Nature hath not been wanting in providing a Remedy against it; as will plainly appear in the following Pages.  
From this manner of their entering the Brain at the same inlet of the Skull with the Arteries, may, for aught I know, be very rationally accounted for that violent troublesome Noise which many, in Distempers arising from the turgescency of the Blood, causing a preternatural beating of the Arteries, do so much complain of; a Symptom happening from the Stricture before mentioned which the unyielding circumference of the Bone occasions upon the different Blood-vessels entering at one and the same Foramen, to which effect also the nearness of the Os Petrosum, through which the Hearing Nerves do pass to this hole, which is in that part of the Wedglike Bone that joins to, or is conterminous with it, does not a little contribute.  
To the same cause, in some measure doubtless, may be ascribed the frequent Headaches happening in Fevers, the Artery then so swelling and compressing the Vein against the edges of the Bone, that the Blood cannot be returned back through it in a due proportion, and consequently by its stagnation the Membrane becomes inflamed and painful.  
So that conformable to what hath already been taken notice of concerning the wise contrivance of Nature, in ordering the different distribution of the Blood-vessels, so as to avoid the Inconveniencies which might accrue to the Brain by compression of the reductory Vessels, occasioned through their entrance at one and the same hole with the Arteries; it seems very much worth our observing, that besides the Veins of the Dura Mater, which enter the Cranium together with the Arteries, as hath before been mentioned, there are also several others belonging to this Membrane, having their rise at, and their descent after a very remarkable manner, from a Vein hereafter to be described on each side of the Longitudinal Sinus, as you may see in the Figure, 
FIG. 4. dd, nn, etc.  and consequently must grow capillary in their descent down from it, after a quite contrary manner to the other; and these do visibly inosculate with some of the Extremities of the aforesaid capillary Arteries, after the same manner as those larger Veins belonging to the Pia Mater do with the Arteries belonging to the Brain and it, by which means it so falls out, that a considerable part of that Blood brought up by the Meninx Arteries, is carried back by these Veins, to the end that, especially in all preternatural swelling of the Blood, the inconvenience of Compression and all its ill consequences happening, by reason of an overfulness of these Vessels, may be in a great measure avoided.   

CHAP. IU. Of the Veins belonging to the Brain itself.  
AFTER this short digression, by order of Method, the Blood-vessels belonging properly to the Brain itself, fall under consideration.  
The curious Anatomist Malpighius, 
Malp. de Cereb. p. 6. par. 2. De Cort. Cereb. p 81 par. 2.  in his Letter to Fracassatus, says, they bear a third proportion to those of the whole Body; and for what reason, seeing, seeing the part itself bears not the same proportion to the whole, it is so, it will be worth our while to inquire hereafter.  
These are either Arteries or Veins. The former go under the name of Carotid and Vertebral.  
The first of which, after a curved passage (which is very well expressed in a Fig. 
Willis p. 29. Fig. 1.  of Dr. Willis) from the place where it gins to enter the Basis of the Cranium (which is from the Styliform Process of the Os Petrosum) to the place where, on the inside, they pass through the Dura Mater, and ascend into the Brain, (which is at the foremost internal Process of the Os Cuneiforme) there is very near an inch and an half distance. I say, after this crooked passage into the Brain, they are propagated quite through its substance, having first divested themselves of that thick Coat borrowed of the Dura Mater during their stay in the passage aforementioned; but not without the mediation or intervention of the Pia Mater, which Membrane all the Branches of the aforesaid, as well as the Vertebral Artery, more or less first prop themselves upon, before they enter on and disperse themselves through the substance of the Brain itself, and is very finely expressed in a Cut of Placentinus, 
Sig. p. 179 Mol. p. 77. Marchetti, p. 191. par. 5.  at the end of Spigelius; insomuch that Molinetti (with whom also agrees Marchetti) looks upon it as only a production of those numerous Vessels; whereas all those little ramifications both of the Carotid and Vertebral Arteries, viz. those: from the carotid Artery, which as soon as it gets through the Dura Mater, and parts with its borrowed Coat, are sent to the 
a Vieussen. p. 35. par. 1. p 34. par. 6.  Infundibulum, 
b Tab. 17. c c.  Olfactory, and 
c Ib. g g.  Optic Nerves, together with those other of the Vertebral Artery which accompany pany the 
d Vicussen. p. 35. par. 1.  third, 
e Ibid.  fourth, 
f Tab. 17. p p. 35. par. 1.  fifth, 
g Tab. 17. TT. Tab. 4.  sixth, 
h h. p. 35. par. 1.  seventh, 
i Tab. 17. Fig. 2. Tab. 4. h h.  eighth, 
k Ib. Fig. 2.  ninth, and 
l Tab. 4. h h.  tenth pairs of Nerves, inasmuch as they enter not the Brain itself, are altogether exempt from that Membrane; any of which now-mentioned Blood-vessels you either find delineated in Vieussenius' 17th Table, or mentioned in some other place of his Book, by those Directions here placed in the margin; all which, tho' existent in Nature, are nevertheless there painted too stiff and formal (I am afraid by guess) inasmuch as that without an injection of Mercury (except those two which belong to the Olfactory and Optic Nerves) they do rarely come to sight in any form at all, Wax being over gross a body to enter such minute Vessels as those are; whereas by an injection with Mercury I find scarce any Nerves but what hath some such small ramifications of Blood-vessels in them.  
To go about to describe distinctly the whole ramification of Arteries through this part, which as was before noted, is here more remarkable for number and size than in any other part of the Body, would not only be to do what in a great measure hath been already done by Vieussenius, in his sixth Chapter, but seem to have also in it much more of ostentation than use.  
I shall therefore only take notice of such propagations of them, as are either remarkable for magnitude, some curiosity of Structure, or useful design of Nature.  
And of this sort may well be esteemed the Vertebral Artery, next after the Carotid, which hath already been described, as entering the Brain at the last and largest Foramen of the Skull, contrary to what Dr. Willis, 
Willis, p. 29. col. 1. par. 2.  and before him Wepfer, affirms, coming thither on each side out of the hole in the transverse Process of the first Vertebra of the Neck, after a very remarkable curved manner, as you see in the Figure, 
Fio. 1. E●  (and by no means like to the delineation and description given by Dr. Lower and Dr. Willis,) ascending laterally upon the Medulla Oblongata as far as the beginning of the Processus Annularis, where they meet together in one single Trunk continuing so the length thereof, 
Vieussen. Tab. 4. bb.  by Vieussenius called Arteria Cervicalis, after which they either send forth two Branches, or receive two from the carotid Artery, by means whereof there is a communication betwixt these two large Blood-vessels, and that of great use and benefit to the Brain, for by this means it happens, that if even three of the four great Arteries which furnish this part with Blood, were totally obstructed, there would yet be a way left for a competent supply from the other unobstructed fourth. These I call the Communicant branches, very ill pointed in Bidloo's ninth Table, but very well in Vieussenius' fourth; as may plainly appear here in the Figure taken exactly from Nature itself. 
FIG. I. dd   
The structure and sinallness of these Arteries seem to suggest two, yet further, provident Intentions of Nature.  
The first is the same it hath expressed in several other places, as in the ascent of the Blood by the Carotid Arteries, both which enter the Brain in a crooked line, the first at the fourth hole of the Basis of the Skull, the second from the hole in the transverse process of the first Vertebra of the Neck, after the manner already in both places described. So in the like manner here, by the narrowness of these Branches, the Blood is in a great measure retarded in its motion to the carotid Artery, and by consequence to the Brain itself, which, for Reasons hereafter to be given in describing the Sinus', would otherwise be in great danger of being overflowed with extravasated and restagnant Blood.  
The second is, a forcing the Blood more plentifully into the Spinal Artery, with which, tho' through the conical structure of the Arteries in common it cannot be altogether unfurnished, yet by its perfectly-reflexed position, would have it very scantily, were it not that by reason of the narrowness of the aforesaid Communicant-branches betwixt the two great Arteries, the Blood was driven back in a sort of a retrograde motion.  
'Tis true, there is a conformation of Arteries something like this, tho' not altogether in the mammary and epigastrick Branches; but 'tis worth noting, that in both these places the main Artery from which these Branches spring is much more taper or conical, 
Ibid. p. c c  and the succeeding exporting Vessels far less both in number and size than those of the carotid Artery here, whose foremost and hinder lateral ramifications between the Lobes of the Brain, bear an over-proportion to the Trunks from whence they come, and consequently must, according to the aforesaid observation of Malpighius,) in his Letter to Fracassatus, receive the blood brought thither far more freely and plentifully.  
Besides, the Cervical Artery here is so far from being Conical, that being made up of two vertebral Arteries joining together, it is much wider than either of them single, as appears plainly in the Figure, 
FIG. 1. g.  and consequently would have carried away the Blood forwardly from the Spinal Artery more freely, had not Nature ordered the Structure of Vessels after another manner here than it does in other parts of the Body, where there is not the same necessity of contrivance.  
One more Branch I take leave to mention only upon the score of its never hitherto having been taken notice of by any, and that's a small Artery attended with a Vein passing through the lateral part of the Os Cuneiforme, (which constitutes the back part of the Orbite of the Eye, just under a very little Process of that Bone, (which either by reason of its size hath escaped being seen, or inconsiderable use, was never before, as far as I know, thought worth the mentioning;) and this, upon raising the fore Lobes of the Brain, offers itself to the Eye of any heedful Observer.   

CHAP. V Of the Sinus' belonging to the Brain.  
A Third sort of Vessels offer themselves next to our consideration, under the general name of Sinus'.  
These formerly were reckoned only four, to which Vesalius added a fifth at the bottom of the Falx, 
Vesal. p. 758 Fig. 3. F.  by him only called a Vein, which tho' frequently found, yet in some Subjects is wanting. 
Board. p. 105. par. 2.  Bourdon mentions two more at the bottom of each side the side the second Process of the Dura Mater, under the lateral ones, which I never saw but once, and I am apt to think with Vieussenius, are most commonly wanting.  
Vieussenius describes four more, 
Vieuss. p. 6. par. 5. Fall. tom. 1. p 114. Vid. Vid. p. 117. cap. 10. p 310. cap. 11.  which I find long before taken notice of, and exactly described by Falloppius, and after him, tho' but rudely, by that laborious Collector Vidus Vidius.  
I think I can show one more, but be their number what it will, I judge it reasonable to look upon them no other than Veins, whether we consider them in respect to either Office or Structure. All the business is, to consider and show for what end they appear as such large Channels into which all the Veins of the Brain, like so many small Rivulets after an unusual manner do empty themselves; and that I will endeavour to do after having first shown their several respective situations.  
The first two are called Laterales, 
FIG 4. BB.  which run within a strong duplicature of the hinder Process of the Dura Mater, down upon the Os Occipitale over the Cerebellum, till in their further descent, after a tortuous manner, upon the lower production of the Ossa Petrosa they wind under them in order to their passage out of the Cranium at the eighth hole, 
FIG. 2. CC.  common to the eighth pair of Nerves going out, 
Ibid. bb.  the third Branch of Arteries belonging to the Dura Mater, and the internal Jugular coming in, which is through two round bony Cells in the Os Petrosa, 
Ibid. L.  just under the Styloeid Processes into the internal Jugular Vein, into which, together with the Vertebral, all the rest of the Veins and Sinus' belonging to the Brain discharge the refluent Blood.  
The next is called the third or longitudinal one, 
FIG. 4. AA, etc.  from its rise at the bony Process called Crista Galli, and progress the whole length of the Brain to the hinder and somewhat declining part of the occipital Bone, where it seems to be cleft into the two lateral ones.  
Into this third Sinus not only the internal Veins of the Brain itself are inserted, but also some of those belonging to its outward Integuments, which Falloppius first, 
Fallop. tom. 1. p. 82. par. 3 Vitus. p. 10. par. 2. Weps. p 42. par 2.  one of the Luminaries of Anatomy, observed; and after him Vieussenius, which are by Wepfer mistakenly taken for Arteries, who nevertheless, for aught I know, may be in the right, in assigning the overcloseness of the Pores of the Cranium (by what Accident soever happening) through which the refluent Blood is transmitted to the Sinus, for a frequent cause of inveterate obstinate Headaches.  
The fourth, 
FIG. 4. C.  which from its situation may not improperly be called the Internal Sinus, comes from the under part of the falcated Process, at that point where it becomes continuous to the second Process of the Dura Mater, 
Ibid. II.  and a large double Vein belonging to the Plexus Choroeides, together with the fifth Sinus, 
Ibid. K.  (when there is one) enters it at an Interstice made between the end of the Corpus Callosum, the Nates, Testes and Cerebellum, from whence having first passed over the Cerebellum, it at last arrives with the other three at that place of union, which from its Author hath ever since retained the Name of Torcular Herophili. 
Ibid g.   
The four others of Falloppius and Vidus Vidius, or Vieussenius, by this last called Superiores and Inferiores, the dd first two of which being longer and narrower, are called Superiores, are on the Basis of the Brain 
* FIG. 2. dd. , arise, according to him, from the Receptacula Sellae Aequinae, by the same Author so named, (hereafter to be described, though more truly, from the ee circular Sinus, 
Ibid. EE  as I hope in its place to make appear, running down from thence upon the internal Process of the Os Petrosum, and terminating in the Sinus Laterales, where they begin to be declive and λ tortuous in their passage to the internal Jugular. 
Ibid. λ.   
The other two, called ee Inferiores, 
Ibid. ee.  which are much shorter and wider than the others, descend from the same place as the former, between the Os Petrosum and Occipitale, down to the aforesaid eighth hole of the Cranium, where the Jugulars come up into the Brain, and end there.  
Another I discovered by having first injected the Veins with Wax running round the Pituitary Gland on its upper side forwardly within a duplicature of the Dura Mater, backwardly between the Dura Mater and Pia Mater, there somewhat loosely stretched over the subjacent Gland itself, and laterally in a sort of a Canal made up of the Dura Mater above, and the carotid Artery on each outside of the Gland, which by being tastened to the Dura Mater above, and below at the Basis of the Skull too, leaves only a little Interstice betwixt itself and the Gland, thereby constituting a Cavity communicating with the two forementioned forward and backward ones, from whence the abovemention'd four small Sinus' do descend, by a visible continuity, on each side from a little beneath the hinder Process of the Sella Turcica: 
FIG. 2. EE  and this from its Figure may not unfitly be called the Circular Sinus.  
Vieussnius, it may be, saw some part of this Sinus where the other four small ones enter it, which is at the hindermost part of his Receptacula Sellae Equinae lateribus adjacentia, so called, and from thence thought those Receptacles to communicate with and to be capable of performing the office he assigns them, (viz.) of bringing back Blood from the nourishment of the subjacent Bone called Cuneiforme, together with the Water separated from the Pituitary Gland, into these four inferior Sinus'.  
Now, as concerning these Receptacles of his, 'tis certain that they are not any where existent in Human Brains, (according to the description he gives of them in the place here noted) seeing both the third, fourth, 
Pag. 16.  two foremost Branches of the fifth, as well as its third hindermost one, together with the sixth pair of Nerves, do not only run out of the Brain enclosed in so many distinct little Capsula's or Cover made of the Dura Mater, during their passage through that part of the Basis of the Cranium by him called Receptacula, etc. but even the whole Dura Mater, together with its Membranous Productions constituting the aforesaid Cover of those Nerves, in that place sticks close to the Basis of the subjacent Bone, (viz.) the External Process of the Os Cuneiforme, on its under side, and to the Carotid Artery (which also both above and below (as was before noted) by its borrowed coat sticks close to the Dura Mater,) on that side towards the aforesaid Gland, leaving no room at all for either Blood or Serum to be contained there, as he would have it; tho' in the same place which he describes for his Receptacles I have in several injected Bodies observed two very fair and large Veins, one coming into the Cranium at the second Foramen from the Orbit of the Eye, (and possibly may be a Reductory Vessel to that part) and so climbs up on the side of the lateral Process of the Wedglike Bone, almost up to the Circular Sinus; the other at the fifth Foramen, which climbs up upon the same Bone till it meet and joins with the other, from whence they make one short Branch, which enters the Circular Sinus very near the place where the two other inferior ones on each side descend down from it; which if they should chance to be cut by accident in any enquiry made into that part, might cause an appearance of Blood, and thereby become an occasion of the aforesaid erroneous Hypothesis.  
Neither is it possible (granting there were any such Receptacles as he mentions) they should serve to the end he assigns, 
Vituss. p. 55  seeing the Glandula Pituitaria is on all sides enclosed by both the Dura and Pia Mater; which first (notwithstanding what he says to the contrary) is on all sides of this Gland of a very strong and equal thickness; yea, in that very part where (as hath been before taken notice of) there is a kind of a Chase made by a certain duplicature of the Dura Mater, constituting the foremost part of the Circular Sinus.  
And if this also was granted, yet would the manner he describes of the Serum or Water getting into these Receptacles (which is by transcolation) render his Supposition very unprobable, seeing 'tis by no means conformable to the Custom of Nature in all other parts of the Body that Arteries should depose a Serum, or any thing else but Blood, (except what goes for Nourishment to the Part itself) in any Part, without being furnished either with its Excretory or Secretory Ductus, neither of which was ever pretended to have been found here.  
And as a thorough confirmation of all this, said in opposition to the aforesaid Hypothesis, I shall only add this, and conclude, that in several Injections made use of in order to find out the use of Parts, I never found one drop of the tinged Liquors on that side of the Carotid Artery, where he hath made the situation of these Receptacles.  
The use of this Circular Sinus is in common with the rest to reduce Blood returning from all the adjacent parts, as the Pituitary Gland, the Wedglike Bone also, and it may be from the Rete Mirabile, which in Brutus' is very large, and therefore seems to require the Service of this Sinus, either mediately or immediately, for reducing a share of its Blood, seeing the Glandula Pituitaria appears no where furnished with Veins terminating any where else sufficient to carry off the refluent Blood from this Plexus, notwithstanding Vieussenius saith on the contrary it hath no Veins, and therefore is forced to have recourse to those small Branches of Veins which accompany the Branches sent out by the carotid Artery, before it perforate the Dura Mater, with the Optic Nerves, or those which go to the Gangliforme Plexus of the fifth Nerve, or those coming out of the Wedglike Bone, for reductory Vessels to this Part; but with what probability I know not.   

CHAP. VI Of the Motion of the Brain and Sinus'.  
TO these Sinus', especially the Longitudinalis, and by way of consequence to the Lateralis also, most if not all the Ancients, as well as Moderns too, particularly Willis and Vieussenius, 
Vitussen. p. 14. par. 3.  have unanimously ascribed Pulsation, after the manner of Arteries, by reason of some Arteries (as they thought) from the Dura Mater terminating in them: of the truth whereof being somewhat doubtful, I resolved to make use of such an Experiment as might remove all future Scruples, and most satisfactorily put an end to the Controversy; which was as follows.  
I took off the upper part of the Skull of a Dog alive, by which means the Dura Mater with its third Longitudinal Sinus lay bare to the Eye and Touch, to neither of which Senses, at first, either any beating of the Membrane in general, or of the Sinus, was the least discernible. After some pause, by chance the Sinus itself, which I designed to have opened with a Lancet, being touched with a cauterizing Iron (which in making the Experiment there was occasion to make use of) poured out the Blood very violently, and at first without any very remarkable pulsation, but altar some time discernible enough, both as to the Blood and Membrane too.  
I cut this Sinus through almost the length of it, to see whether any Arteries (whereof many, according to Vieussenius, which was also long afore affirmed, and that upon Experience too, by the learned Wepfer, did terminate in it, and so occasion its beating, 
Wepf. p 116 par. 1. ) would discover themselves by throwing out their salient Blood, but no such Sign appeared.  
After all which 'tis manifest the Sinus' themselves have no pulsation, other than what is communicated to them from the subjacent Brain, which contrary to what Bourdon affirms, hath an evident pulsation through the multitude of Arteries dispersed through 
Board. p. 196. par. 2.  it so forcible as to create a sensible Systole and Diastole in its outward cover.  
'Tis worth noting, that while the Blood-vessels are all full, so as to keep the Dura Mater upon its full stretch, the pulsation is not vi sible at all, or at least very faintly; but after a depletion of the Vessels, so, as that grows somewhat more lax, the beating becomes very visible, equally in the Sinus and Membrane too.  
After having made this Experiment I found one Author of the same opinion, and that is Falloppius, who in vindication of Galen against Vesalius, his Contemporary, says, all I have said upon the foregoing Experiment, and all the great Vesalius was able to answer in his own vindication in his ingenious Book called Anatomicam Gabr. Falloppi Observat. Examen, falls very short of its aim.  
As to the Transverse Ligaments which are in some places 
* Fig. 4. r.  round, cordal, and in others 
† Ibid. x.  broad or membranous, in the Longitudinal Sinus chief, both serving for Strength and (in concurrence with the cruciform ligamentous Fibres, taken notice of by Vieussenius, on the under and outside of this Sinus, from whence the Fibres belonging to the falcated Process aforementioned seem to have their original,) Elasticity to this part for its more vigorous reduction of the Blood passing through it, together with its blind Cavities or Diverticulums serving to moderate the over-swift or violent motion of the Blood; seeing I find them so exactly described by Vieussenius, to whom the Reader may have recourse, I think their description need take up no room here.  
But as to the manner of the Veins entering this Sinus, I find it far different from that which is described by Lower first, 
Low. fig. 4. h h. Vituss. tab. 2 D D, etc.  and afterwards by Vieussenius, both whom make them enter with their Orifices from behind forwards, (two or three only excepted by Vieussenius) and that for some other useful purposes than what have hitherto been taken notice of.  
And this is as follows, 
Fig. 4. dd, etc.  (viz.) About one half of them (tho' intermixedly) (but all, after having first upon their arrival at the Sinus insinuated themselves for some space alter the manner of the Pancreatic Dust or Ureters first taken notice of by Lower, 
Ib. dd, etc.  betwixt the Duplicature of the Dura Mater) from behind forwards, the other half from before backwards, as in the Figure.  
Now, by this contrivance 'tis plain, that first of all there are made two contrary Torrents in one and the same Channel, by which means the refluent Blood, made poor by the vast quantity of its richest parts drawn off as it were into Animal Spirits, through a collision of Parts, which by this contrivance must needs fall out, is preserved in its due mixture, which when at any time lost through the languishing of its intestine motion or elasticity, retards even its circular or progressive motion, which when it happens but in some degree, is the cause of many Distempers; and when altogether, of Death itself.  
In the next place the circulation is at all times not only somewhat retarded, and the Blood hindered, (together with the help of the bony Cell at which the internal Jugular Veins enter the Sinus') especially in an erect posture, from descending with that rapidness and weight it would otherwise have done upon the descending Cava to the Heart; but also much more so retarded in a supine position of the Head, a posture most natural and ordinary for Mankind to take their rest in, through which contrivance, in concurrence with that of the Lateral Sinus', (whose structure is such, that in the aforesaid posture the Blood is forced to climb upwards before it can arrive at the place of its descent into the Jugular Vein) there is made a more plentiful generation of Animal Spirits, one chief Cause of the great refreshment and vigorous disposition of the whole Body we find after Sleeping.  
As to the other manner of the Veins entering this Sinus, (viz. from before backwards) it from thence happens, that in a prone Position of the Brain, a posture not uncommon amongst Men, the Blood is helped forward in its circulation through the Sinus; the truth and design whereof are at once both evident and pointed at by Nature from the Structure of this part (and which therefore shows the great usefulness of Comparative Anatomy) in Brutes, who by reason of such a Position, which the necessity of Feeding almost always keeps them in, have always such a disposition of this Part, to assist the Blood in its heavy circulation.  
The design of Nature in making these Channels so wide on a sudden, in respect to the Branches of Veins lately treated of terminating in them, seems to correspond with the conformation of the Parts just now treated of, and with that it had in making the Ramifications of Arteries afore taken notice of so large and unproportionable to the Trunks from which they spring, which is a flower than ordinary circulation of Blood through the Brain, in order to make a still more copious production of the Animal Spirits so called. Which profitable Design and End of Nature had nevertheless been attended with a very great Inconvenience, (viz.) an extravasation of too much Serum, the usual effect or consequence of a slackened Circulation, had it not been for another provident Contrivance of Nature in the two Communicant-branches, betwixt the Carotid and Vertebral Arteries aforementioned, p. 36. by the narrowness of whose Channel the influent Blood is in some measure repressed in its motion, and an overcharging the Vessels with Blood prevented.  
These Sinus' differ in structure one from another, the Longitudinal and Lateral ones having many transverse Ligaments which the other have not, and the Longitudinal having many small Cavities or blind Diverticulums, as aforesaid, which the Lateral have not; the use of them all being for strengthening and defending them from giving way to the violent irruption of Blood into them, against which sometimes notwithstanding they are not able to defend themselves; as I have seen in many Skulls ni which the Blood hath burst open the sides of the Sinus' and found its way between the Duplicature of it, so as even to have made a Fovea or Cavity in the Cranium itself, as was before noted, one of which I have now by me.   

CHAP. VII. Of the Plexus Choroeides.  
THIS Plexus is an aggregate Body made up of Arteries, Veins, Membrane, and Glands, double on each side, (which hath not before been taken notice of) and consequently having two Originals.  
The first Original is from the foremost Branch of the Communicant Artery, 
FIG. 1. ee.  which running backward up betwixt the hinder Lobes of the Brain, (in which for some part of the way it is immerged, and to which it gives many large Branches) and the Medulla Oblongata at length arrives at the Lateral Ventricles, 
FIG. 5. ee.  and makes one part of the Plexus on each side.  
The second Original is from the hindermost Branch of that Communicant Artery, 
FIG. 1. second ee.  which running more backwardly, ascends betwixt the hinder Limbs of the Brain and the Cerebellum, till it comes to the Isthmus, where communicating with the first Branch abovementioned, they make a reticular broad Expansion, which covers both Nates, Testes, and Glandula Pinealis, 
FIG. 5. GG  and constitutes the second or other part of the Plexus Choroeides.  
The first Branch gins to divide itself into divers Network Foldings, interspersed with Glands somewhat what before it enters the Ventricles, 
Ibid. 5.  and continues such to its Extremity on each side, where they both under the Fornix wind cross the third Ventricle into a mutual inosculation.  
The second gins to assume the same shape or contexture as soon as it gins to enter the Isthmus, continuing such throughout its entire abovementioned Expansion.  
These two on each side are joined together by a twofold connexion, the first is by an Artery running under the Bombyces, intervening betwixt them, which could not be here inserted so as to come in view.  
The second is by a production of the Pia Mater, which is extended all over these parts of the Lateral Ventricles, and the third Ventricle which lies betwixt the first two parts of the Plexus forwardly, and down to the other two hinder parts of the Plexus backwardly under the Fornix and Septum Lucidum; so that whatsoever Water is transmitted out of these Ventricles, must slip down not only under the Fornix, but that Membranous Production itself; from which kind of structure and position of this Membrane may probably be understood how there might happen such an Hydrocephalus as the learned Tulpius mentions, 
Tulp. lib. 1. cap. 24  in which there was found above two pounds of Water in one Ventricle, without any at all in the other: and such another as Wepfer mentions, 
Wepf. p. 69  where the Water causing the Hydrocephalus in an Heifer, was found contained in a Cystis, and that only in the left Ventricle too: for, supposing this membranous production of the Pia Mater to be double here, as it certainly is in all other places, 'tis not difficult to conceive, that the Water which is extravasated must needs insinuate itself betwixt the two Lamina's, till by a continual increase it extends them into the shape of a large Bladder, such a one as the latter found there and drew out with his Fingers; and that which seems to put out of all Controversy that it was so, is, that in those places, both above towards the Corpus Callosum, and below on the Basis of the Ventricle, he found some sort of Asperities as though the Bladder filled with Water had been covered with some small Protuberances not much unlike to White Poppy-seed, in those places where it was contiguous to them; which Protuberances doubtless were the small Glands interspersed quite through this Plexus.  
How this Distemper came to be on one side only, though sometimes it is on both, as you may see in another place of the aforesaid Tulpius, may likely enough be from an Adnascency of both the Lamina's of this Membranous Production, 
Willis p. 10 col. 2. par. 1.  in that place where the Septum Lucidum sinks down from the Fornix, occasioned by some small sort of pressure of the superincumbent Brain. Besides these Veins, which are very truly described by Willis, I have always found two more meeting the foremost Extremities of this Plexus, from between the two first Lobes of the Brain, where it seems to end under the foremost part of the Corpora Striata, by which it is there fixed and as it were kept in its due situation: and from these Branches are on each side sent forth many more little ones to the Corpora Striata, and several other parts adjacent.  
To this Plexus belong also Veins, which from the Extremities of that part of it in the Lateral Ventricles begin to come into two distinct pretty large Trunks, 
FIG. 5. hh.  running down through the middle of the third Ventricle, as far as the fourth Sinus, and there receiving some Branches from the other hinder part of the Plexus spread over the Isthmus, discharge the refluent Blood into that Sinus.  
But besides this sort of Reductory Vessels, 
Ibid. qq.  it hath also another, (viz.) Lymphducts, which I first discovered in the Brain of a strangled Body, and showed to several then present, running in different ramisications amongst the reticulated Vessels and Glands of this part: Which Observation being added to that of the great Anatomist Anthony Nuck, who in that curious Piece called Adenogrophia says, 
Nuc. p. 150.  he saw one coming from the Glandula Pinealis, and that his Friend another Anatomist, whose Name he mentions not, (but I know it was one Bodivol, whom I had the Happiness to be very well acquainted withal, now dead) sent him word, he saw another not far from the aforesaid place; may be of sufficient authority to evince the real Existence of these Vessels hitherto so much enquired after, in the Brain as well as in other parts of the Body.  
The Glands belonging to this Plexus are very many, but very small, and their Use, according to all the Moderns, especially Willis, Duncan, and Vieussenius, to carry off the redundant watery part of the Blood, but that without ever showing by what rational contrivance of Structure it can be done, seeing none of them ascribe a Secretory Dust, which must always be in readiness when any unprofitable part is to be discharged.  
Since therefore this part is found furnished with Lymphducts, 'twill be no hard matter to conceive the genuine use of the Glands, which is, to separate a rich nutritious Juice from the influent Blood, and by the Lymphducts to refund it to the refluent, after the loss of its noblest parts left behind in the Brain in its passage to the Heart again.  
It may also, for aught I know, according to the Opinion of Willis, serve to warm its neighbouring parts the Internal Superficies of the Brain, which being purely medullary, hath not so plentiful a share of Blood-vessels dispersed through it as the rest, and consequently, to maintain an equality of warmth conducing so much to the conserving the Spirits in their due vigour and exercise, must borrow an additional supply from hence. It is situated upon the middle of the Thalami Nervorum Opticorum, all-along them length way, and, contrary to what Willis says, is, by virtue of several Blood-vessels, joined to that medullary part of the Brain so called, immediately lying under it.   

CHAP. VIII. Of the Rete Mirabile.  
NOtwithstanding the Opinions of the late Wepfer, Willis, and Vieussenius too, (which too last indeed, tho' but now and then, are willing to allow it an existence only in Men, (who nevertheless, if the Supposition of Willis be true, viz. That such cannot but be Fools) had better be without it, 
Willis p. 2●. col. 2. ) together with almost all the Ancients, as Vesalius, Columbus, etc. to the contrary, I have never found this Rete wanting, or with any difficulty discoverable in Men, springing from and lying on the inside of each Carotid Artery, in that place of the Circular Sinus chiefly which looks into the four abovementioned inferior and superior Sinus' in the Basis of the Brain, and in some measure also the whole length of the Sella Turcica, on each side, between the Gland and the Carotid Artery.  
And that it is so small in them with respect to what it is in Brutes of several kinds, is no way surprising, when consideration is had to the Use and Service of it in those Creatures, who, by reason of their prone Position, would otherwise be in danger of having their Brains deluged as it were with an overgreat quantity of the Influent Blood, and of a Rupture of the Vessels, by its violent ingress, and this Danger so much the more threatened by how much the same Cause which brings it into the Brain with that force is equally as great and effectual to hinder its proportionable return; for the relief of which Inconveniency Nature hath contrived a means of its more easy and safe descent into the Brain, by turning that one large Stream of Blood, (which through its being penned in one Channel, becomes so rapid) into many more, (by which means the Carotid Trunk above the Dura Mater in those Creatures is very small to what it is beneath, whereas that Artery in Men, etc. hath the same bigness on both sides that Membrane,) and they not only reticulated and contorted for the more slow and laborious (which Contrivance the Ancients thought was only for a more exact preparation of the Blood for Animal Spirits) descent of the Blood, but also many of them by their insertion into the Glandula Pituitaria attended with small Veins issuing thence, to take off some part of the burden too.  
This last contrivance of Nature methinks may be sufficient to render that Controversy of Vieussenius with Willis (which, before them, 
Vieuss. p. 16 pat. 2.  was betwixt Waleus and Rolfincius) the two latter on each side denying this Rete to have any Veins, very needless; seeing that if the Pituitary Gland have any, which I am confident it hath, (notwithstanding the positive Assertion of Diemerbroeke, 
Diemerbr. p. 364. par. 3.  in order to serve his own most unprobable Hypothesis, to the contrary) as having seen them plain injected with Wax; then this part of the Blood in some of the Branches of the said Rete, which are plainly inserted into the Gland, is equally capable of being reduced by those Veins without any necessity of having recourse to those remote Branches Vieussenius hath been forced to seek for, 
Vieuss. p 45 par. 2.  as if it had had them of its own.  
And that to the aforesaid Position of different Creatures ought chief to be ascribed the variety of Magnitude of this Rete in several of them, its size in Dogs seems highly to evince; in which, by reason of their Horizontal Position, being neither so prone as several Brutes who seed on Grass, nor so erect as Man, that Rete is found smaller than in the first, and larger than in the last.  
Another Use it hath been thought to have, is, to carry off a considerable quantity of a dull watery part of the Blood, in order to the production of the finer Animal Spirits; and this it is thought to effect by means and help of the Pituitary Gland, betwixt which and itself there is constantly observed a greater affinity, the one being either greater or lesser in proportion as the other is so, and betwixt, which there are in all Creatures, but more remarkably in those where they are both large, a distribution of several Branches coming from the aforesaid Rete. And this is looked upon by Vieussenius so considerable an office of the Glandula Pituitaria, that in those Creatures where it is but small, as in Men, Horses, Dogs, etc. he hath substituted many, 
Vieus. p. 102 par. 3.  but particularly two Cavities, for that use in the Wedglike Bone, just under the Sella Turcica, in which he supposes that part of the aforesaid Serum, which by the smallness of the Rete cannot be returned that way, is remitted by several little Arteries slipped off from the Carotid, whilst under the Sella Turcica, terminating in the two abovenamed Cavities, there either deposing a part of the Serum to be carried off by a strange way he there mentions, (viz.) by two holes, into the Nostrils, and thence into the Fauces; or else by certain Veins meeting them in that place, as their proper Reductory Vessels, 
Vieuss. p. 9 par. 2.  to the Heart.  
Now, as to this office of the Glandula Pituitaria, I cannot easily be persuaded it is either designed for, or capable of it, till such time the Abettors of this Opinion can be able to show me it furnished with an Excretory Dust for this purpose.  
And if they offer, that the Veins are such, I reply, That (besides its being very unprobable that so vast a quantity of Blood as continually is brought by the Carotid Arteries to the Brain, should be able to get rid of any considerable quantity of its Serosity, by so small a part as the Glandula Pituitaria is;) 'tis not the usual way of Nature to part with any Share of its Juices out of its Vessels, when so unactive and unprositable as this is, and immediately to receive it in again, seeing it is provided of Emunctories enough to convey it away by.  
Moreover, granting (which by no reasonable means is to be granted) it were so as they would have it, yet nevertheless, in conformity to Nature's proceed in all suchlike case, there ought to be an intermediate passage by way of a Secretory Dust, which none hath been able hitherto to discover.  
And so far as Vieussenius seems to be of this opinion, 
Vieus. p. 102 par. 3.  which in one place he plainly is, making it of so gross and viscid a nature, as is only sit to be discharged at the Emunctory of the Nose; the same Reply is satisfactory: But when by way of flat contradiction to himself he comes to make the same gross Humour a perfect fine Lympha, the Answer is then, 
Vieuss. p. 54. par. 1.  That there is no need of parting with it beforehand, seeing we find that Liquor only separated by the Lymphducts of the Brain afterwards.  
Seeing therefore there is such an affinity as before mentioned, between the Rete Mirabile and Glandula Pituitaria, and taking it for granted, that the office of the Glandula Pituitaria is not what it hath generally hitherto been believed, to the end we may attain a more exact knowledge of what it really is; it seemeth not altogether immethodical to take that part into consideration in the next place, together with the Infundibulum, which last hath not only as near a relation to the Gland as the Gland hath to the Rete, but such a close communication with it, that it seems in a manner almost impossible to treat of one independently on the other.   

CHAP. IX. Of the Glandula Pituitaria, and Infundibulum.  
THIS Gland is seated in and fills up in a manner all that space contained within the Sella Turcica (Vessels only excepted).  
'Tis covered on all sides with the Pia and Dura Mater, excepting that part on its upper Superficies, in which there is a little round hole, by which the Infundibulum descends slopingly into it, being at its entrance environed with a Production of the Pia Mater, for its more firm connexion with that part, as was before noted.  
But as to the Dura Mater, it encompasses it after a far different manner than what Vieussenius hath described, 
Vieuss. p. 51 par. 5.  not suspending it in Man as it doth in Brutes, so as to hinder it from touching the bottom of the Sella, and that forasmuch as there is not the same reason for its so doing in one as there is in the other, for in Brutus' the Rete Mirabile is not only situate on each side this Gland, but: runs quite under its hinder part, by which one side of the Rete communicates with the other, a Disposition of this Part which Vieussenius was altogether unacquainted with; whereas in Man, inasmuch as there is not that sort of Structure in the one (i. e. the Rete) 'tis not nccessary it should be required in the other.  
However, in neither one nor the other is the Reason which Vieussenius gives for Nature's contrivance of this affair of any weight, seeing neither the Rete Mirabile, 
Vieuss. p. 50 par 1.  much less the few small Veins belonging to the Bone beneath, could possibly any way be compressed by this Gland, though superincumbent, because it is so firmly knit to the Dura Mater, lying above and upon it, which is supported by the two foremost and hindermost Processes of the Sella Turcica, in such a manner as is sufficient to sustain and keep from pressing upon any subjacent part ten times a greater weight than the Glandula Pituitaria is.  
Moreover, the Dura Mater is so far from suspending it from that Bone, that it is, together with the Gland, fixed to that very Bone itself.  
The substance of this Gland is far differing from that of all the rest, which I have often upon this account particularly examined; in consistence indeed 'tis the same with most of the Conglobate kind, if not somewhat harder, but then being pressed or squeezed, it emits much more Water than any of them.  
As to the Conglomerate sort, it hath not the least resemblance to any of them, and consequently cannot be supposed, as it hath hitherto been by all, to carry off any excrementitious or unprofitable pare of the Blood.  
Now, if we consider this part, together with the appended Infundibulum, we shall certainly find a conformation far different from any other part in the whole Body of Man, inasmuch as that which this Gland receives by the Infundibulum, or which is the same, what this Infundibulum conveys to it, is not separated from the mass of Fluids by any visible Secretory Dust, which in its ordinary method Nature is observed constantly to make use of, whensoever it parts with any part of the Blood, whether excrementitious or reductitious, throughout the whole compages of the Body.  
Nor hath the manner of Nature in transmitting a certain Liquor to the Gland been less abstruse in carrying it off from that part again, the reductory Vessels from the Gland being equally concealed, as the adductory to the Infundibulum; that way of Transudation, according to the invention of Vieussenius, being to the greatest degree improbable, as having no resemblance to the course of Nature throughout the whole Body.  
Nay, even a possibility itself seems hardly allowable, if we take but notice of that part in Brutes in whom its Integuments are extraordinary dense, the Dura Mater, as he truly observes, investing it close on every side, (and which he perceiving, and consequently foreseeing what might from thence unanswerably be objected against him) was forced to make them much more than in Men; in which last indeed there is seemingly. some reason for its being so, 
Vieuss. p. 52 par. 2.  inasmuch as the Rete lies in a Duplicature as it were of the Dura Mater, on each side of the hindermost part of the Sella Turcica, as tho' one Lamina of it was spread upon the subjacent Bone, and the other over the Pituitary Gland, (a disposition contrary to that in Brutes, as hath already been taken notice of) but nevertheless there is no necessity that it should be so divided in this place, nor doth the said Author ever offer a Reason for its being so, (which looks as though his Assertion was only a Guess) seeing this Membrane can send out new Productions as well double as single, as we find in its two eminent Processes before described, and Sinus'; agreeable to what it also therefore may and does do here, where the Integuments of this part appear plainly to be of too thick a consistence to admit of his imaginary way of transudation, which is manifest not only by sight and section, but in that by the greatest force made use of in compressing and squeezing it between one's Fingers, we find it impossible to force out the least appearance of Humidity through its aforesaid Enclosure or Integuments,  
Being therefore very inquisitive after the true use of this part, and despairing of ever attaining to such a Knowledge without first knowing the exact Structure thereof, besides all other means commonly made use of in all Anatomical Inquiries, I made use of all sorts of Injections serviceable to such an end, as of tinged Liquors, Wax, and Mercury, but all with little, if any, success according to my expectation, the Wax not penetrating its Texture at all, the tinged Liquors but very superficially, and the Mercury, (where my chief Hopes were) always by its weight (do what I could to the contrary) either breaking through the sides of the Infundibulum, where it leaves the Brain, or else falling down in greater Globuli than the extreme narrow Passages were capable of admitting. and by this means became altogether useless.  
Being compelled therefore for the present to leave off a little while a further enquiry into the Structure of this part, by reason of the great mist it is involved in, and to gain a little more Light for our Guidance in searching after Truth, (which like many other things of greatest value lies deep, and is with great difficulty accessible) it may not be amiss to see what Assistance can be had, by making diligent Scrutiny into the Structure of its Appendix the Infundibulum.  

The Infundibulum.  This is a thin medullary Dust, covered with the Pia Mater, descending from the internal Concave Superficies of the Brain, to which, by reason of its wideness towards one end, and narrowness towards the other, in resemblance to a Tunnel, as well as by reason also of the parity of their Uses, the Ancients gave the Name of Infundibulum.  
In Man it is closely inverted with the Pia Mater at its very entrance into the Gland, and from that place hath not any manifest Cavity I could discover by blast or style, but is altogether of a medullary substance, contrary to what it is in Sheep or Calves, in which last Creature, where the Parts are larger, by inserting a Blow-pipe into that part of the Infundibulum, next to the Gland, I have seen its further Tract or Passage on the upper part thereof a little puffed up, and a considerable quantity of Water regurgitate, as though it had lain contained either in some Pipes or Porulous Substance of that Gland.  
This Difference is not take notice of by Vieussenius, and therefore what he says of this part seems chief in this respect, if not altogether, applicable to the Structure it hath in Men.  
Those two Divisions or Ramifications of this part the said Author mentions, 
Vieussen. p. 49. par. 3.  one forwardly, and the other backwardly, in Sheep, Calves, etc. I have always found correspondent to the Descriptions he there gives of them; but whether the first be protended so, and terminate after the manner he there describes I somewhat scruple, seeing I have always observed the Extremity of that part in Brutes, towards the foremost part of the Gland, sinking as it were into the very Substance thereof, and afterwards becoming presently altogether imperceptible, and in Man the termination thereof just after the same manner, save only that in the last it happen forthwith upon its approach to the Gland, without being protended either backwardly or forwardly.  
The Use of this part is certainly to convey some sort of Humidity from that great concamerated Cavity within the Brain, resulting from its inward complication of parts, to the Pituitary Gland, and the office of it is to receive and carry off this transmitted Humidity; but as to how either this Humidity is collected in the aforesaid Cavity, or how, when conveyed into the Gland, it is carried off, we are still as much in the dark as ever.  
I know very well there is nothing more easy with the Visionary Philosophers than such a Knack as this; and now I think on't, the great Willis makes nothing of turning a Vein into a Lymphoeduct in the Glandula Pinealis and Plexus Choroeides, 
Will. p. 46.  no less than which does also the accurate Vieussenius, 
Vieus. p. 110 par. 3.  in the Plexus belonging to the fourth Ventricle; but how consonant this is to the rational structure or mechanism of parts, neither the one or the other have been so kind as to explain.  
Now, as to the Plexus and Glands before mentioned, 'tis evident by what hath been already discovered and accordingly given an account of in the preceding Pages, they are furnished with Lymphoeducts, as proper reductory Vessels; so that so far the Prophecy is vanished.  
But as to the remaining Gland, I am not so fond of guessing to say it hath any, and consequently all I can say is, that as I look upon the Infundibulum to be no more than a large Lymphoeduct variously ramified through the Glandula Pituitaria, discharging its Liquor by those many small Branches into the Veins dispersed through that part to be reduced after the manner 'tis in all other Secretory Glands back to the Blood gain.  
And that which seems most to favour this Conjecture, is the extraordinary humidity of this Gland, especially in Brutes, above the rest of the whole Body, as serving not only to export what Lympha is separated from several Arteries dispersed through it, but that also which it is charged with from the Brain itself.  
And to this twofold manner or double office of Secretion is owing the two distinct Substances it seems to consist of, the one being accommodated to that part of the Lympha coming from the Brain, and is therefore whitish, the other to that separated immediately out of the Blood, and is therefore reddish.  
Lastly, As to the manner how the Lympha passes down through the Infundibulum passes down through the Infundibulum from the Brain to the Glandula Pituitaria, I look upon it to be in the form of condensed Vapours arising from the Arteries of the Plexus Choroeides, emitted thence for the keeping moist and in good order that inward Production of the Pia Mater, spread all over its Parietes, which being a membranous dry part of itself, might otherwise become injurious to that fine medullary part lying under and being contiguous to it; in which there is a continual motion of Animal Spirits, whose Tracts, and consequently they themselves, through any the least intemperance of this Membrane, would be in great danger of either some obstruction or disorder.  
And that this Lympha is only the result of the aforesaid Vapours, I am the more readily inclined to believe, because I never saw Water in that part of any sound Brain, nor unsound neither, where the Plexus Choroeides was firm; and there was no reasonable ground, by the extravasation of Serum in some other remote parts of the Brain, to believe it had its rise from thence.   

CHAP. X. Of the Glandula Pinealis.  
THE Gland called Pinealis, from its Figure, is about the bigness of an ordinary Pea, prefixed to the two Prominencies called Nates, hereafter to be described, at the end of the third Ventricle, immediately under the broad and hinder part of the Fornix, (with which nevertheless it hath no connexion, 
Vieuss. p. 71.  as Vieussenius saith it hath) and over that part of the Rima in the third Ventricle called Anus.  
'Tis joined to the Nates by several Fibrous Roots, and becomes a support to that part of the Plexus Choroeides there situate.  
In an hydropical Brain of a strumous Boy, I have seen it swelled to a size of three times its ordinary magnitude, and by reason of the abundance of stagnate gelatinous Lympha contained in it, perfectly transparent.  
Hence it most plainly appears that this part is a mere Gland, and, by what was said before conformable to what hath been observed in this hydropic Brain, of the Conglobate or Lymphatic kind, and by consequence a very unfit part to be made a Receptacle of Animal Spirits, 
Vieus. p. 71.  as Vieussenius makes it, and much more a place of residence for the Soul, according to Des Chartes.  
'Tis true, there are two fair medullary Tracts arising seemingly from the two Roots of the Fornix, stretching length-way upon the Thalami Nervorum Opticorum, as far back as this Gland, (by Vieussenius called as this Gland, 
Vieuss. p. 6● par. 3.  (by Vieussenius called Tractatus Medullaris Nervorum opticorum Thalamis interjectus, as though it was only one, and accordingly is so delineated by him, Tab. 7. GG, but indeed is two, one on each side) about which place they turn in, and by a transverse bending kind of a Process (by the same Author called Tractus medullaris natibus antepositus) unite, as he hath exactly observed: 
Willis, p. 9 col. 1. par. 1.  And this, doubtless, gave occasion to the Error of Des Chartes, as Willis truly thought, (whose sublime and most deservedly-admired Philosophy had doubtless been much more useful, had he conversed more with Dissections, and less with Invisibility) and Vieussenius too, 
Mural. p. 508. Will. p. 10. col 1. par. 3  (with whom in the same Mistake doth agree Muraltus and Willis) for upon a more heedful inspection (as was most evident in the Brain aforementioned) it will be found that no part of the Process aforesaid, however near it comes to this Gland, does in any wise become continuous to it.  
Dr. Wharton also stumbled upon these medullary Tracts, 
Whart. p. 141.  placing them amongst the Nerves themselves, and ascribes the same unreasonable use to them as he does to the Nerves in many other Parts of the body, (viz.) of separating a superfluous Humour from the Cruca Medulla Oblongata, or Thalami Nervorum Opticorum, (being the same Part, and only on the other side or upper part of the Brain, under another denomination) which he supposes to be the Commune Sensorium.  
It hath Arteries and Veins in common with other Glands, the Veins ending in the fourth or inward Sinus; as may the Lymphducts too, when they are conspicuous.   

CHAP. XI. Of the Brain in general.  
THAT part of this Treatise relating to the Vessels, being dispatched, I shall in the next place proceed to an account of the Brain itself, under which term are generally comprehended the Cerebrum and Cerebellum, and Medulla Oblongata, which Parts being in many respects so different one from another, may justly challenge a distinct and orderly description.  
The Brain then, in the first place, as distinct from the other two, is that large and almost spherical Body which comes first to sight in the old way of Dissection, filling the greatest part of all that space contained in the Cranium, consisting of two different Substances (first taken notice of by Archangelus Piccolominius) both in Colour, Consistence, 
Piccolom. p. 252.  and Office, the one being more compact, white, medullary, or fibrous, the other softer, greyish, and glandulous.  
The utmost Malpighius (by virtue of his Microscopes) could do, 
Malp. De Cereb. Cort. p. 78, 81. par. 3.  was to discover the Cortical part to consist of Glands of an oval depressed Figure, and in his Opinion, of the Conglomerate kind, (but that how properly, as also his calling the Nerves their Excretory Ducts, I leave to the Judgement of others) and the Medullary part to consist of various Fibres immerged in and having their original from the aforesaid Glands, deriving from them a certain Liquor called Nervous Juice, concerning the Existence of which, in the usual sense 'tis taken in, as a fluid body, contained and running continually in the Channel of the Nerves, as Water in Wooden or Leaden Pipes, for either Nutrition or Censation, is a thing somewhat improbable, it being not only possible, but very easy to resolve those two Phoenomena's, the first from the Blood, and the other from the Natural Tenseness of Sensible Parts maintained by the supply of a proper Liquor from the Blood, both in their Originals and continued or elongated Productions; inasmuch as it doth as certainly circulate in them as in any other parts of the Body. And as to the manner how this is done, it will appear very plain and intelligible, after the innate Structure of the Part hath been more accurately enquired into.  
The Curious Lewenhoeck made a far deeper scrutiny into these two Parts, 
Lawenh. de Struct. Cereb. p. 37.  being very probably assisted by better Glasses, and from what occurred to his view, called the cortical part a pellucid Vitrious Oily Substance, (the seeming oiliness of which Substance I attribute only to the stagnating of the pure Liquor, growing cold after death of the Creature,) from such a close and regular Position of the Globuli swimming therein, as allows the Rays of Light to pass them without refraction, contrary to what they do in the other or medullary part of the Brain, in which they are so disposed that the Light cannot pass them in right lines, and consequently being a little distorted, makes them appear white, notwithstanding Malpighius on the contrary neither allows the Parts of the Brain to be diaphanous, 
Malpig. de Cereb. p. ●.  nor the Animal Spirits to be any thing akin to Light.  
'Tis true, even by his own confession, that his most nice and diligent Inspections could not free him from many Scruples about what he saw; yet some things to our purpose were plain enough, as Reticular Bodies of a red colour, which being larger in the Cortical Parts than Medullary, helps to give it that greyish or subrunneous colour, as he calls it.  
Nextly, a transparent Vitrouscoloured Substance contained in most minute Vessels; whence 'tis plain there are two sorts of Liquors in this Cortical Part, one of a red colour, or Blood, contained in larger Vessels, whose Globuli, which give it its redness, either by reason of their size or figure, cannot enter those small Vessels which with the Fluid contained in them constitute this transparent, cineritious, or cortical part of the Brain.  
The other a transparent Liquor, contained in most minute Vessels, as aforementioned; from whence I am induced to believe this Cortical part to be only an Aggregate of different Vessels, (as also I do of all the rest of the Parts of the Body) containing different sorts of Fluids'.  
Of these Vessels some contain a more compound Liquor, commonly called Blood, which whilst in that state, by reason of the Globuli swimming on it, looks red, and by reason of a tubulous Poor of a proper size and figure so continued to the Vessel we call a Vein, that it undergoes a continual quick circulation.  
Another sort of Vessels there is which receive and contain a more simple fluid body, of a thin transparent nature, which when in some parts of the Body, gives the name of Lymphducts to the Vessels that it runs in; but when in these Vessels, which are discovered to make up the great Substance of the Brain, whether Cortical or Medullary, may be allowed the name of Fluidum Animale.  
And this last sort of Vessels I look upon to be either a certain Protension of an Artery, by its smallness rendered capable of holding such a sort of Liquor only as the last spoken of, or else such a tubulous production of the Artery as by its Orifice of Poor answers to the figure and size of the Fluid it is by Nature intended to receive.  
Upon the same exact Enquiry made by a Microscope, the medullary part of the Brain appears to be of the very same constitutive parts, ranged only after a somewhat different manner, which makes this part appear more white, as was before observed. But over-and-above (if it may be allowable to make a Conjecture) I am inclined to think the Whiteness of this part may be owing in some, if not the greatest part, to such a narrowness of the Vessels discovered here, containing the pellucid Substance aforementioned as will not entertain any Fluid whatsoever, without its being first reduced into very minute Particles, or Septometry so called: Which last Vessels I therefore suppose to be only yet more Capillary Productions of the aforesaid Cortical Vessels, as they are of the red or Blood-vessels endued with such a Poor as fits them only for the reception of a most subtle, fine, soft Liquor, which I esteem the true Medullary and Nervous Juice, which being contained in its proper Capsula, and many of them collected into one Fasciculus, at its egress out of the Brain, being there wrapped up in more thick and strong Cover made of the two outward Membranes of the Brain, do constitute that part we call a Nerve, which having all its Integuments or Membranous Enclosures always kept turvid and tense by its contained Fluid, after a slow and leisurely manner continually dispensed from the Fountain, and by its growing more taper towards the place of its termination, by which means it acquires a greater straightness or narrowness of its Pores ordinarily called Fibrillae, it so falls out that all inward Impressions, upon all occasions, are the more easily and speedily transmitted through it.  
The very same notion also concerning Nutrition (which in the truest sense is only an apposition of Parts nourishing to Parts pre-existent to be nourished) in the rest of the Parts of the Body, I have thought reasonable to entertain ever since, by assistance of the Microscope I have plainly discerned the Veins to be only continuations of Arteries, and the Blood to run in the same Channel variously modified, without the least suspicion of Extravasation, (viz.) a continual transmission of Nutritive Juice out of the Pores of Arteries, after many wind like Tindrils of Vines (Analogus to which the red Reticular Bodies of Lewenhoeck seem to be in the Brain,) grown very capillary into certain Tubulis or Pores of a corresponding bigness and figure, making up the whole fleshy part of the Body, whose Substance, when 'tis freed by washing or injection of Water, we see to consist only of large and small Blood-vessels and Fibres; which last, whether Nervous or Membranous, or such as relate to Muscular Motion, commonly called Carnous, I suppose to be full of minute distinct Vessels for the communicating and receiving their proper Liquors or Fluids after the manner already expressed, which as contained in the said Tubuli or Pores, whilst they retain their Natural Constitution and Proportion, I presume it is which keeps the Habit of the Body plump and vigorous, the more thin and languid being perpetually carried back by the Lymphatic Vessels, and a great part wholly exterminated by mere simple Transpiration; which I adventure to think is not only superficial from the Sudorific Glands in the Skin, but also through the whole Substance of inward parts, through small Canaliculis or Meantus' in even the Viscera themselves; by which, not unlikely, we may guests at the Meaning of Hypocrates, when he said, All things were conspirable and transpirable.  
The minuteness of Vessels is that which hath so embroiled the Thoughts of Naturalists upon this Subject, and set Realities so remote from the Understanding, otherwise 'tis no Paradox to affirm the Existence of Vasa Vasorum almost to Infinitum, some containing Liquids in a continual more nimble circulation, others in a gentle protrusion only: Which will appear altogether unsurprizing, if it be considered that the aforementioned Ingenious Author hath computed, that even the 64th part of a Myriad (i. e.) of a Ten hundred thousandth part of any Substance but as big as a small grain of Sand, 
Leweth. p. 46.  cannot, especially if of a rigid or inflexible nature, enter those little Vessels, which are seen in a retiform manner distributed amongst, and fixed to the aforesaid pellucid Globules, which swimming in those little Vessels, are discovered to make up both the Cortical and Medullary part of the Brain. As also further, that even the tender Coats of the smallest of those Vessels which contain the aforesaid most minute Globular Fluid Bodies, 
Lewe●●●●  are also full of yet far more minute Vessels than they themselves are.  
Nay, I am so far from being surprised at this kind of Vascular Constitution of Parts, that I apprehend not how Nature could otherwise have acted without the consequence of a boundless Accretion, inasmuch as that when any parts of a Fluid become extravasate, they necessarily lose much of their progressive motion, and if of a gross consistence, are either proscribed by the wider passages, or of a finer, through those more strait and elaborate (viz.) by Transpiration; so that what Particles of Matter soever continually arrive, for either the augmentation or reparation of the Parts, must (unless the ruin of the Subject do not first happen, as we see it often does in Diseases proceeding from such Causes) needs (if not confined in Vessels) advance into a monstrous preternatural accumulation, as being, by reason of their gross consistence, altogether uncapable of being carried off proportionably to the measure of their aggestion, in the form of subtle Steams or Exhalations.  
Besides a rational explication of the natural Functions which this Hypothesis furnisheth us with, it also, seems to clear a great many Difficulties which have hitherto puzzled the most refined Physiologists relating to the Animal Faculty, such as are Sensation and Muscular Motion; of which last here in the next place, the other being reserved for the last Chapter, which treats of Sensation and Motion in general.   

CHAP. XII. Of Muscular Motion.  
TO recite the Opinion of others upon this Subject would be a thing altogether useless here, seeing an Abstract of them is already extant in the Philosophia vetus & nova by Mr. Colbert; and besides, the most correct of them are not only very unprobable, but absolutely repugnant to plain Reason and Matter of Fact too; an Instance whereof you may have in Dr. Willis's Tendinous Reservatories of Animal Spirits, 
Willis de Mot. Musc. p. 35. Mayow de mot. musc. p. 73.  in Dr. Mayow's Twisting or Fiddlestring Fibres, with whom of late Mr. Regis agrees, by which the Muscle must needs lose a great deal of its thickness, than which nothing is more contrary to Experiment; in Duncan's first and second Element of Des Chartes, 
Dunc. p. 90  which he makes the Animal Spirits to consist of, contrary even to the very Principles of that great Man's Philosophy, which allows no Elasticity to those Bodies themselves, though the Authors of it in all others; likewise in Dr. Croon's making the Blood itself, 
Croont, p. 23, 24, 25, 33. Philos. c●●. p. 23.  as well as the Animal Spirits, to be moved by the power of the Soul to any Muscles; as likewise the extravasation of those two Liquors first into the spaces betwixt the Fibres, and then their introvasation into the Fibres themselves again, in order to make inflation, an Error incident to the Immortal Borellus also, 
Borel. de mot. Ati●. p. ult. prep. 23. & ●●ribus ●l●s loci●.  whose imaginary Discourse upon this Subject seems of a very different Thread from the rest of his Excellent Works.  
If therefore what hath been already said about the Structure of Parts be remembered, (viz.) That the Medullary Part of the Brain is only a Contexture of Vessels; that its Nervous Propagation or Nerve is also a Compages of Vessels, formerly called Filaments, much more narrow than those of the Brain itself; and, that these Nerves produce, or at least terminate in the Fibres of all sorts of sensible Parts whatsoever, though of a different texture, as well as those carnous ones of Muscles, which last are tubulous, 'twill not be in the least unreasonable to infer, That these Bodies being kept continually turgid with the contained Fluid, are equally capable of transmitting or receiving Impressions of the Object, as if they were stretched longitudinally like a Bowstring from each Extremity, according as Borellus hath observed.  
And as to Muscular Motion, allowing only what may directly be inferred from what hath previously been said, (viz.) That the Nervous and Carnous Fibres are only a congeries of Fluids' contained in certain Vessels communicating with each other, that by reason of a Plenitude in the aforesaid Fibres, the whole Machine is in a constant Equilibrium, it will necessarily follow, upon the common Postulatum, (to which all Mankind must be beholdden upon all such Explications as these to the World's end) viz. that the Sensative or Rational Soul can command the Animal Spirits (which I call only a Nervous Fluid) into a Primus Impetus, or local motion, that a part of that Liquor, whenever a Muscle contracted is transmitted through the Vessels which contain it from the great Reservatory thereof, the Brain, to its Carnous Fibres, into whose Vessels, being so much narrower than those of the Nerves, even by virtue of the same force which moves it from the Brain, that Liquor is driven after a most rapid manner, (which Effect, to any acquainted with the nature of Fluids' and mechanical Laws of Motion by Projection, needs not any demonstration) causing the Intumescence or Inflation of the Muscle, the same Liquor at the same time being driven back again with an equal speed from the Antagonist Muscle into the room of the first, which was transmitted from the Brain to the contracted one, in order to maintain the same Plenitude or (which is the same thing in the sense of the old Philosophers) to avoid a Vacuum. And if any object the wideness of the Passage it is to come back by from the reflexed Muscle, as an impediment to an equivalent speed in that Liquors retrocession, I have to answer, that the Emptiness being made first, is a sufficient recompense for that.  
And here I cannot but take notice, that all they who contend for Animal Spirits, analogous to those we see produced from various Subjects by Fire, as the only adequate medium for all sorts of Muscular Motion, have been forced to have recourse either to certain Tracts or Interstices betwixt the Filaments of the Nerves continued from the Brain, or the Original of the Nerves through their whole Productions to the Muscle, of which sort are the Cartesians, or else to a certain Nervous Juice, for their place of residence, of which sort are most of the Moderns, and particularly Vieussenius, by which Passages, or out of which Juice these fine invisible things are either voluntarily, by the command of the Soul, or inadvertently, from several either inward or outward impressions, transmitted, in order to produce Motion: which if true, and the only ways of producing Muscular Motion, I beg leave to ask, how it comes to pass, by either of these ways, that when another person bends my Arm, and that againfl my Will too, the bending Muscles of the Arm become as tumid as when voluntarily or inadvertently contracted at any other time; which hath been truly observed tho' not satisfactorily accounted for, by Dr. Croone, 
Croone, p. ●●  or any other I know of.  
But how this or any other sort of contraction of a Muscle happens, does by the other aforementioned Hypothesis become explicable, without any manner of difficulty at all: For when the Cause of Contraction is from the Command of the Soul, the pressure is first from the Fluid in the Brain, by which all the interjacent or continued Fluid slows towards the Part to be moved, the same proportion of Fluid being at the same instant transferred into its room from the relaxed Muscle; and when the contraction of the Muscle is from the abovementioned external force bending the Arm against my will, than the Liquor contained in the relaxed carnous Fibres or Vascula is transmitted through the whole continuity of Fluids', to that which is contracted, and all this without being beholden to the wild Conceits of a dry and moist part of the Nervous Juice, blind Passages, invisible Tubuli betwixt the Antagonist Muscles or Valves in the Nerves, by a mere Aequilibrium of the Fluids contained in the Vessels the Parts consist of.  
At the same time I am not insensible of the Solution some have given this Instance of Involuntary Motion upon another Hypothesis, (viz.) by supposing an equality of Tension or Elasticity in all the Muscles of the whole Body; by which means it falls out, that when any new additional force (though never so small) is added to the Fibres of any Muscle, as in voluntary motion, or the power of Elasticity in the Antagonist Muscle, overcome by outward force, as in the aforementioned Instance of Involuntary Motion, the other Muscle than becomes contracted.  
Now, that this is one concurrent Cause in both sorts of Instances, as being confirmed by the Experiment of cutting a Muscle through, either towards the Extremes or in the middle, by which the Fibres, by their natural Elasticity, are found to contract either to one or the other, or to both Extremes, is allowed to be true; but to be the only Cause, is altogether as false.  
For, in the first place, as to the case of voluntary Contractions, it is allowed to proceed from a transmission of Spirits from the Brain into the carnous Fibres, (that Hypothesis of Steno to the contrary having been convicted long since by Borellus, in his Book De Motu Animalium) though not without the concurrence or sympraxis of the natural Elasticity of the Fibres belonging to the Muscle to be contracted.  
So likewise, without the transmission of Animal Spirits from some force or another, I deny even the possibility of that stiffness or hardness which is easily preserved in all contracted Muscles, feeling and seeming as though they were indurated and swelled out, as really they are, whether it be in the case of voluntary or involudtary motion; in confirmation of which, I affirm, that though by the cutting of the carnous Fibres of any Muscle through, which way soever it be, the contracted part may, and doubtless does, grow thicker by the shortening of its Fibres, yet by that means only it does not become stiffer and harder, so as we find Muscles do when contracted by any natural Cause, nor is there any necessity it should do so, according to any Rules of Mechanism, seeing the Fibres shortening only by their own elastic force, when they find the circumambient space give way have no necessity of subintration of parts, which is always requisite to procure a stiffness or hardness to a part altering its dimensions as Muscles do, from a longer and thinner to a shorter and thicker circumference; and upon this it must needs follow, that in a Muscle contracted by involuntary force (in which Action the Brain is altogether unconcerned) that stiffness or hardness then perceivable in it, must needs be owing to the Fluid or Spirits in the antagonist Muscle, after the manner already explained, transmitted to it.  
Now, to define what sort of thing this Animal Fluid (so called) is, I see no occasion to frame any other Idea of it than what we ordinarily have of the purest Liquors, seeing the Nerves are a Substance which (to the Senses of either Smell or Taste discovers very little else than what is insipid) are always reckoned amongst the least hot parts of the Body, and doubtless far less warm in Fishes than us, who yet have as great a stock of Animal Spirits as any other Creatures. And this Consideration may be it was that occasioned an Author to give the Animal Spirits the Epithet of Frigidiusculi. 
Du His. T. l. p. ●●●   
'Tis plain enough, that the Vessels which contains this Fluid are extreme minute, and consequently the Content must needs be of a very fine and depurate consistence, though without much resemblance to either the aforesaid nimble, saline, or sulphurous Productions of the Fire.  
'Tis in a continual, gentle, direct motion, though perhaps contained in curved or reticulated Vessels, from its original source to the ends of the carnous Fibres, from whence it is conveyed into the Membranous or Tendinous Productions, according as the Fibres terminate, and it may be by filtration only; in which, as in other, and particularly in Glandulous Parts not subservient to Muscular Motion, where Nervous Ramifications are very copious, whether it be of any other use than to keep the Parts in their proper tone, in order to their regular discharge of the office of Secretion, must still remain a Controversy, notwithstanding all that hath been yet advanced against it, inasmuch as wastings and numbnesses of Parts, the common Symptoms of obstructed or divided Nerves, (which doubtless by their hastening through such Causes to Muscular Parts, gave the first rise to that Conjecture about the Existence and Use of that Juice throughout the whole Body) are equally explicable by the want of Tone, as of that supposed Liquor.  
To the proof of all this an Experiment frequently made does not a little contribute, and that is the injecting the Arteries of a Dog, or any such Creature, when dead, upon which there immediately happens a contraction of the Muscles, according to the different strength of them, (viz.) of the Extenders in the hinder Legs, and of the Benders in the fore Legs, though the Injection be only of cold Water, the reason of which effect in particular, if it be remembered what hath been before observed, (viz.) that the Blood-vessels do most certainly enter the composition of the Nerves themselves, will not only become very easily explicable, but the whole Hypothesis at least very highly probable.  
If it be said, That this speedy instantaneous reflux of the Animal Fluid is opposed by the aforementioned constant direct motion it hath from its Source to the parts to be moved, 'tis easy to reply, That its slow direct motion that way is easily overcome and repelled by the violent impulse of the forcibly-relaxed Muscle the other way.  
If further it be demanded, by what means it so happens that in the Instance before us of an Arm bend by force, that the refluent Animal Fluid is rather towards the Muscle, which by that means than proves contracted, than towards any other whatsoever, to all which it may indifferently have access, I think the Solution seems not difficult, if it be considered, that at the same time that the one Muscle is forced from, the other is forced into a contraction; from whence it so falls out, that the carnous tubulous Fibres of the last, which by being extended under the state of relaxation, did lose their cavity, must needs by their natural elasticity, when freed from the preponderant force of its Antagonist, acquire it again, by which means a space being made, the repelled Fluid, by the Laws of Libration, (to say nothing of the habitual motion of the Animal Spirits, or Liquor, by most Authors, especially Borellus, urged as a Reason for this effect) must needs be driven thither.  
In fine, though I am not averse to think most of the Phoenomena relating to Sensation and Motion may be solved by this Theory, tho' of so small an apparatus, yet I am so far from being fond of it, that I have reserved a far greater share of Friendship for any other that may seem but of never so little more a kin to Truth, and submitting all I have said on this Subject to the candid Sentiments of the more judicious Proceedee in describing the other parts of the Brain as they offer themselves in the usual modern way of Dissection.   

CHAP. XIII. Of the Brain in particular.  
THIS Part being already described and considered in general, as consisting of two different Substances commonly called its Similar Parts, and the Source of all Sense and Motion, comes now to be taken notice of in a more particular manner, with respect to its dissimilar parts or conformation; and this I think may best be done first according to its outward, and next to its inward appearance.  
Outwardly 'tis convex and cortical, exactly divided into two Hemispheres by the first Process of the Dura Mater called Falx, from the bony Process called Crista Galli forwardly to the very hindermost part of the Cranium, where these two Divisions are stretched over the Cerebellum, from which part also 'tis perfectly separated by the second Process of the Dura Mater, to the end it may not cause any prejudicial compression upon that part, either by its weight or pulsation.  
The foremost Division is made only as deep as the Corpus Callosum, the latter to the very Medulla Oblongata itself.  
'Tis further imperfectly divided into four Lobes, two whereof (which being the less) are forwardly, and two (which are much bigger) backwardly.  
These Divisions appear best in the inverted or Varolian Dissection, being marked out as it were by four Branches of the Carotid Artery, two before, and one on each side.  
These I call Imperfect Divisions of the Brain, because though the Pia Mater runs betwixt them, together with the aforesaid Branches of the great Artery, yet they adhere by several Fibres, both of that Membrane and the Blood-vessels themselves.  
'Tis also imperfectly divided through all its external cortical part by the Pia Mater, though not so profoundly, to the end the Blood-vessels may penetrate this part in more sine and reticular Ramifications; and that by the pulsation of the Arteries the interjacent cortical Glands, (or rather Vessels) may more freely make their proper Secretions.  
Nextly, it may be considered in its inward appearance, which is concave and medullary, taking its original from the Extremities or Apices of the Medulla Oblongata, (or rather a little more forwardly from the foremost part of Vieussenius' oval Centre) commonly called Processus Lentiformes, or according to Dr. Willis, Corpora Striata.  
From hence 'tis presently reflected back on each side in the form of a Vault, very near as far as the Nates and Testes, a little below which on each side 'tis joined with the Crura Medulla Oblongata on their under side, being continuous there to those Parts commonly called the Crura Fornicis.  
The middle and uppermost part of this Medullary Substance, by the Ancients always called Corpus Callosum, is therefore by Vieussenius called Fornix Vera, 
Vicus. p 61 par. 1.  in his Opinion sustaining that Office (though I see not that it does, or for the Reasons before given in the description of the Dura Mater and ' its Processes, needs to do any such thing.)  
This is that part which, as was before noted, was thought (but mistakenly) by Vesalius and others to escape the covering of the Pia Mater and in it are not visible any bloody Specks, as in most other parts of the Medulla Cerebri.  
'Tis the medium uniting the medullary part of each Hemisphere or Division of the Brain, famous for the transverse Stria running through it from each side of the aforesaid Hemispheres, the Septum Lucidum only coming between.  
In this large or principal Cavity are contained the three Ventricles, the Fornix, the Septum Lucidum, Corpora Striata, Thalami Nervorum Opticorum, the Roots of the Fornix, the Tractus Intermedius of the Corpora Striata, the Tractus Medullaris Thalamis Nervorum Opticorum Interjectus, (which last has been already described) the Vulva, Anus, and Rima or Passage to the Glandula Pituitaria by the Infundibulum, and Glandula Pinealis, (which also hath already been described) of all which briefly in their order.  
The three Ventricles, 
FIG 5. AA  by cutting asunder the Fornix near to its Roots, and turning it backwards over the Nates, 
The three Ventricles.  Testes, and Glandula Pinealis, appear to be but one, those on each side it being called the Laterales, in which are the Corpora Striata Thalami Nervorum Opticorum and Crura Medulla Oblongata, that Rima, so far as 'tis covered with the Fornix and parts the Crura Medulla Oblongata, being the third.  
From the extreme Limits of these two side Ventricles, 
Vieuss. T. 10 AA, etc.  from before to behind, 
Centrum Ovale.  does arise that medullary space called by Vieussenius, Centrum Ovale, in his Opinion the great Dispensatory of Animal Spirits, the fore part whereof Willis calls Limbus anterior corporis striati. 
Will. De An. B●ut. p 42. T. 8. F.   
The Fornix is a medullary part arising from two Roots in the foremost part of the Basis of the Brain, 
The Forix. FIG. 5. AA, bb.  lying betwixt and upon the uppermost parts of the Thalami Nervorum. Opticorum, which Roots come out of the foremost part of the Geminum Centrum semicirculari, so called by Vieussenius, like two large Nerves, and afterwards join together, constituting a broadish medullary Body, which after having first projected itself for some space forwardly betwixt the Corpora Striata, and afterwards run the length of the third Ventricle, growing all the way broader and broader, and towards its edges (by Vieussenius called Fimbrae) thinner; 
Vi●ussu Tab 6. D  and being reflected backward towards the hinder part of the lateral Ventricles, like two Arms, commonly called Crura Fornicis, the beginnings whereof on each side are by Aurantius called Hippocampi and Bombyces, 
Aura●. Anal. O●. p. 45.  (from whence, I know, he had chief observed this part in Brutes, in which, by virtue of the hinder part of the Fornix, in that place growing somewhat thicker, and running over the hinder and upper parts of the Th. Nerv. Opticorum, which are more prominent in them, as in Sheep, Calves, etc. than in Men) it is made to appear on each side like the bending Crest of the Sea-horse, and is in colour much like the Silkworm. certain minute Stria's, 
Malp. de C●r●b. p. 5.  which Malpighius calls Fibrae, crossing them like Rings obliquely, contrary to what the same Author's Account is of them, who says those Fibrae or Striae run upon them otherwise, viz. as they do on the Septum Lucidum (i. e. longitudinally) and embracing the Th. Ner. Opt. on their upper part on both sides, but adhering close to them as one continued Substance on their under part, (in which place they are called, by Vieussenius, 
Vieus. p 61.  Posteriores veri fornicis (viz. Corporis Callosi) Columnae) becomes there continuous with the hinder part of the Corpus Callosum, where it winds down upon the sides of the Crura Medulla Oblongata, 
Ibid.  and makes up that undermost space or cavity of the two side Ventricles, by the said Aurantius called Ventriculi Hippocampi or Bombycini, and Vieussenius called the hinder part of the Centrum Ovale, which by that kind of curved passage loses something of its oval figure.  

The Septum Lucidum.  The Septum Lucidum some of the Moderns think to arise from the Fornix, thence ascending to the internal Superficies of the Corpus Callosum; others from this last descending down to the Fornix, but most likely from this last, where towards its foremost part I have always sound it double, (first taken notice of by Silvius de le Boe) and as Vieussenius truly says, 
Sylu. deal Boe Disp. Med. p. 19 par. 1. Thes. 13.  often with Water in its duplicature.  
'Tis a very thin, medullary, transparent Body, intermediate to the Corpus Callosum and subjacent Fornix, by means whereof the two lateral Ventricles are in that place separated one from another.  
The Corpora Striata, 
The Corpora Striata, FIG. 5. I 1, etc.  or Processus Lentiformes, are two Prominencies situated something higher than, and in Men a great part of them on each side (though Dr. Willis says, where the Corpora Striata ends the Thalami Nervorum Opticorum gins, which is only so in Brutes) of the Thalami Nervorum Opticorum, or Juga Crurum Medullae Oblongatae, and are so called from the many white Streaks appearing in them, descending obliquely to the Medulla Oblongata, with Cineritious Substance coming betwixt them when they are cut horizontally.  
They run down on each side the Thalami Nervorum Opticorum as far as till the Corpus Callosum gins to wind back upon the Crura Medulla Oblongata, towards the hindermost part thereof.  
I have got them delineated here exactly true, (tho' by neglect without the Striae) finding all the Cuts of them in Willis to be from Brutes, except one, which is done very ill, and those in Vieussenius very false, unless in Figure the 8th, which also wants the Striae.  

The Thalami Nervorum Opticorum.  The Thalami Nervorum Opticorum are two prominent Bodies, more purely medullary on their outward Superficies than within, which meeting together like the two topmost strokes of a Y inverted, constitute the uppermost part only of the Crura Medulla Oblongata in that form, the other or undermost side being quite of another figure; and seeing they are the immediate continued Productions of the Medulla Globosa Cerebri, (which contrary to the old Opinion of Praxagoras and Philotimus, asserting the Brain to be only a Germination of the Dorsal Marrow, of late revived by Bartholine, 
Causab. ●n Athan. p. 137.  (if any precedency of Parts as to time may be allowed) I look upon to be rather the original than the production of the Medulla Oblongata and Spinalis too) and may more properly be called Capita than Crura of the Medulla Oblongata.  
The Tops or Juga do, 
FIG. 5. cc.  as already observed, incline close, yea, join together, as Vieussenius hath rightly observed contrary to Willis, (whose Figures of that part are utterly false) unless where the Rima ad Infundibulum parts them, leaving like the Corpora Striata an obtuse angle between them.  
Betwixt these two last mentioned Bodies there is a medullary space on each side, which in a bending manner encompasses the Thalami themselves, and receive the Extremities of the Striae in the Corpora Striata, as they descend from the aforementioned Centrum Ovale, and is therefore by Vieussenius called Geminum Centrum Semicirculare, 
Vieus. p. 67. par 2. Willis de An. Brut. p. 42. T. 8. 〈◊〉.  by Willis Limbi Posteriores Corporum Striatorum  
The reason why they are called Thalami Nervorum Opticorum, is from certain Fibres supposed to be in them, arising both from their true medullary Superficies (by Vieussenius called a Medullary Membrane) and some from within their own Substance, which at last, towards their foremost part meeting together, make up the Bodies of the Optic Nerves.  
Willis says nothing of these Fibres, though in his Opinion Galen did not improperly give them that name. Vieussenius paints them very strong.  
As for my part, I never could find any Fibres at all appearing in their external medullary part, those within are very small at best, and scarce discernible.  
On the outside of these I have always found and often showed a very fair medullary Tract, 
A Medullary Tract. Tab. 5. mm  here described, running all-along betwixt the Corpora Striata, &c from the very hindermost extent of the Corpora Striata forwardly, down to the very Roots of the Fornix, to which they seem to be continuous.  

The Passage into the Infundibulum  Within this Cavity of the Brain are likewise two passages into the Infundibulum, and so on to the Glandula Pituitaria, the foremost of which is called by the odd Name of Vulva, 
The Vulva.  and the hindermost of Anus, 
The Anus.  from their situation, which with the Rima betwixt them, is called, as was before noted, the third Ventricle.  
The places whence all this Water issues are commonly by the latter Anatomists described under the name of Tria Foramina, 
Tria Foramina.  situated so as to give passage from all the eminent Regions of the Brain, from whence there can be access had to them for the Water (or rather the Lympha, properly so called) to fall into the aforesaid Infundibulum, the first whereof is behind the Testes, under the Valvula major, (hereafter to be described) the other just under the Pineal Gland, or the beginning of the Rima, which two meet in an Aperture, under the Nates and Testes, 
Vieus. p. 73. par. 3.  by Vieussenius called Aquae Emissarium, having a steep descent into the Infundibulum; and the last at the end of the Rima, or just under the Roots of the Fornix, and all ending at length (tho' by two different passages) in the Infundibulum.  
It may not be unseasonable in the next place to take notice of two remarkable very fair Processes, 
The Nates and Testes Tab. 7. CC  called Nates and Testes, by former Anatomists so named from the resemblance they had to those parts; but it is plain from thence they were only used to dissect Brutes, in which they have such a proportion as is betwixt them; whereas in Men 'tis plain they are very near of the same size, and not very different in form, being oblong and accuminated towards their Extremities; but in Sheep, Calves, and most other Creatures the Nates are round and large, and the Testes oblong, somewhat accuminated, and very small.  
Before these Natiform Processes, under the Glandula Pinealis, runs a transverse Process before taken notice of Pag. 84, 
Vieussen. Tab. 8. f  by Vieussenius called Processus Natibus Antepositus, and Nervuli Aemulus, which upon further enquiry, by drawing the Thalami Nervorum Opticorum still wider, appears to be rather Nervi than Nervuli Aemulus, being as thick as that behind the Roots of the Fornix, to which in situation 'tis just opposite, and seems to join the Thalami Nervorum Opticorum together, as that does the Corpora Striata.  
In what rank to place them 'tis hard to say, as being neither proper Appendices to either the Brain or Cerebellum, properly so called, and being divided from the Medulla Oblongata in some measure by an Interstice commonly called Ductus ad Infundibulum by the Moderns, but by the Ancients a Passage for the Animal Spirits to the fourth or noble Ventricle.  
They are situated upon that part of the Medulla Oblongata which is between the Cerebrum and Cerebellum, 
The Isthmus.  which space was before called Isthmus, opposite to that part called from its Author Pons Varoliis, and by many Authors, as Bartholine, Spigelius, Highmore, etc. thought to be the two hindermost Roots of the Spinalis Medulla, which much more likely Riolanus makes the Processes of the Cerebellum to be, 
Visalius p. 766, 767. fig. 10. AA, I, K. & fig. 11. GG.  and with him the great Vesalius, who paints them so.  
From this intermediate situation Dr. Willis thought sit to make them as it were an Intelligence Office betwixt the Cerebrum and Cerebellum, how rightly, I refer to the Judgement of others.  
'Tis certain they are medullary Bodies, and contribute to the making the Animal Fluid or Spirits so called after the same manner as the rest of the Brain does; for in cutting them through, (after having taken the reticular expansion of Blood-vessels off from them, which is very large here, and eminently conspicuous in injected Brains) I find them of the very same substance with the Processus Annularis and the Thalami Nervorum optici, partly cineritious, and partly medullary, and in fresh Brains somewhat, but very faintly, striated.  
I know not of any part within the Brain, properly so called, that is not already described, except a certain Medullary Chord at the end of the third Ventricle, and the Valvula ●●ajor.  

Commislura Crassioris Nervi A nula of Vieussenius.  The first of these is a Medullary Process, 
Willis p. 43 col. 2. Vituss. p. 83.  which joins the Corpora Striata together, according to Dr. Willis, by Vieussenius called Comissura Crassioris Nervi aemula; and according to him is the Medium or Commissura by which his Geminum centrum semicirculare intervening between the two Corpora striata, superiora anteriora & posteriora, and his Tractus medullaris transversus & obliquus intervening between his two Corpora striata inferiora anteriora and posteriora, have a communication with each other.  
Dr. Willis places this Chord or Commissure under the Roots of the Fornix, but it is always behind it, 
Willis, p. 6. col. 1.  tho' contiguous to it.  
The second is the Valvula major, 
The Val●●la major.  so called by Vieussenius, 
Vieus. p. 76. Willis, p. 49 col. 2. pat. 2  but plainly enough discovered by Dr. Willis long before, and its proper use described.  
It is a thick (especially in Men) medullary Membrane, adhering forwardly to the inferior part of the Testiforme Process a little behind that transverse medullary Process from whence the pathetic or fourth Pair of Nerves arise, laterally to the Process ascending from the Nates to the Cerebellum, on its hindermost Expansion, to the foremost Vermicular Process of the Cerebellum, and no where that I know of to any part of the Pous Varoliis, as Vieussenius will have it, 
Vieussen. p. 76. Id. p. 73. par. 3.  (who seems to have mistaken another part for that Process) unless just where the second Process of the Cerebellum comes out from thence, which jointly with its fellow Process on the other side, when they meet together, after their transverse descent on the backpart of the Medulla oblongata, do really make up that part which by Willis is called (and that no doubt from Varolius) Protuberantia Annularis, and by others, from its true Author, Pons Varoliis.  
By raising up the foremost abovementioned Vermicular Process of the Cerebellum with the Finger, it rarely fails to come in sight; but if not so, 'tis easily shown, by blowing into the Foramen situated under the Pineal Gland.  
It's use, according to Vieussenius, 
Vieus. p. 110. par. 2.  is to hinder any part of that Water which falls into the hindermost Foramen behind the Testes, from running into the fourth Ventricle, or Vice versa from the fourth Ventricle into it, or from getting out on each side of the Medulla oblongata, over the aforementioned Processes, so as to fall down upon the Nerves arising thereabouts below from the Medulla oblongata: Which last use is evidently most true, (whether it be understood of Water preternaturally or accidentally collected there, for I must needs confess I could never find any there, any more than I could in the third Ventricle in Subjects free from those Diseases incident to that part, as hath before already been remarked p. 82) but as to that relating to the passage from the Cerebellum to the last or third Foramen, I much doubt the Truth of it, for many Reasons, of which this is one, viz.  
That the Plexus Choroeides in the fourth Ventricle, together with the adjacent Parts, being of the same Texture as the other are in and about the two lateral ones of the Brain, renders it as reasonable to suppose that Water may be collected there as in other parts of the Brain, (nay, that it is so, he himself also allows as Matter of Fact) and consequently as necessary to have a place of vent for the Water whenever it happens to gather there, as it was for that which was at any time got into the other Ventricles. And consequently,  
In the next place, I do not see how this tender Film can be able to intercept a passage of so searching a body as Water at any time forced against it (notwithstanding the supposed declivity of this Part, which in Man, by reason of the largeness of the subjacent prominent annular Process, is very inconsiderable) which by Pulsation must needs happen whenever we suppose that Cavity filled with it.  
And, in the last place, notwithstanding all the Contrivance the aforesaid Author hath shown in conveying the gross part of the Water (which, as was before noted, he grants may be, nay, constantly is deposed there from the Glands of the Plexus Choroeides here situate) by the Extremities of Veins, out of this Ventricle, 
Vieus. p. 111  I am suspicious, if there was no speedier reductory passage found out, there would frequently happen very great Mischiefs to the Medulla Spinalis itself, and the Nerves springing from it, seeing the Extremity of that Ventricle called the Calamus Scriptorius is there parted from the Spinal Marrow behind it, but only by the Pia Mater, which notwithstanding it is there double, as it is also quite down the whole Spine, lest perhaps the Water should fall down upon the Nerves which arise from it too readily, yet upon such an occasion may be easily supposed subject to violation. Not to say any thing of the high improbability of any such Conveyance at all by the Veins, seeing that in a natural state they are always, as hath been already observed, continuations only of Arteries.  
'Tis true, this may hinder the fall of Water into the fourth Ventricle, by reason of a Passage under the Nates before mentioned, by Vienssenius called Aquae Emissarium, so near at hand to receive it when it finds its further passage that way obstructed by the interposition and resistance of this Valve. And for the same reason doubtless it was, that in Vieussenius' Experiment which he brings for a Proof of his Opinion, no Water was found in the sourth Ventricle, 
Vieus. p 110 par. 2.  it having got a passage immediately, upon its non-admittance by that Valve, to convey it another way, which by reason of the steepness thereof, is done much more readily.   

CHAP. XIV. Of the Cerebellum.  
THE Cerebellum falls next in order to our consideration, in describing of which I hope a great deal of pains may reasonably be spared, seeing all that hath been already spoken of the cortical or cineritious part of the Brain, as also of its medullary part, is equally applicable to the Cerebellum. Nor is what hath been said already of the Plexus Choroeides in the Ventricles of the one part less applicable to that Plexus in this.  

The Plexus Choroeides of the Cerebellum.  This Plexus Choroeides in the fourth Ventricle gins to be glandulous just under the Eighth Pair of Nerves, from whence it runs up on the side of the Caudex Medullaris to the chordal or third Process of the Cerebellum, and from it enters the fourth Ventricle, 
Aurant. Anatom. Obs. p. 48.  by Aurantius called Cisterna Spirituum, (which Ventricle, conformably to what that Author hath in the aforesaid place observed, I always find broader than long, and double, though not divided by any intervening Body, as the two lateral ones of the Brain are;) not lying lose therein, nor at the bottonn of it, as the Plexus does in the Ventricles of the Brain, but quite contrariwise, (and which hath not heretofore, as I know of, been taken notice of) adhering close to the top of this Ventricle, or the bottom of the superincumbent Cerebellum, then running transverse just at the end of the Calamus Scriptorius, there becomes continuous to the Plexus of the other side; as hath been observed of the Plexus in the lateral Ventricles of the Brain.  
This Plexus arises from a ramification of the second or backwardest Branch of the Cervical Artery, as one part of the other Plexus of the Brain mentioned in that Chapter where the said Plexus is treated of, doth) and another smaller Branch of the said Artery about the place where it ascends from the Vertebrals, which last Branch turns into a reticular Expansion first, 
FIG. 1. q  and then a little space further meeting with the other, constitutes this Plexus.  
This part differs from the Brain in its cortical structure, inasmuch as its Interstices are here eliptical or pieces of imperfect Circles, growing shorter towards those two Productions of the Cerebellum, before and behind, (which by reason of certain annular depressions occasioned by Bloodvessels there embracing them, seem as tho' they were wrinkled like Worms, and therefore called Processus Vermiculares) as Parallels upon the Globe do towards each Pole.  

The three Process of the Cerebellum.  It hath three Processes, which joined together on each side, make up as it were two fair Roots, according to the Ancients called the hinder Roots of the Oblongata Medulla, by the Moderns Peduncles or Stalks, by which this part grows to the Medulla Oblongata.  
The first of these ascend from the Cerebellum to the Nates, 
FIG. 7. gg  the second from the Cerebellum to the Medulla Oblongata, 
FIG 6. BB.  which meeting together on the under side thereof, as was before noted, make up that large Protuberance by Willis called Processus Annularis, 
Var. Anat. p. 26.  by others from the first Author Pons Varoliis.  
This I sinned full of Stria's or medullary Tracts, 
F 10.6. cc  much stronger and larger than those of the Corpora Striata, running transverse on each side the length of the whole Process, and terminating in a medullary long Tract, dividing that Process into two equal parts, as you see in the Figure, 
Ib. cc  the use whereof, as having never been before observed will be hereafter taken notice of.  
The third descends from this part backwards, 
Ib. ss FIG. 7. hh  upon the upper side of the Medulla Oblongata, like two longish thick Chords on each side, making the Medulla look somewhat thicker and broader in that place, and not unfitly styled the Chordal Process.  
These Stalks, when they join together at the other end, make up the Meditallitum or Corpus Callosuas of the Cerebellum.  

The transverse Process of the fourth Ventricle.  There are two or three fair medullary Processes close to, and sometimes riding one over another, a little on this side the fourth Ventricle, or about the beginning of the Calamus Scriptorius, which join the two cesses together that descend from the Cerebellum to the Medulla Oblongata; and there are two more deseending length-way from that other transverse Process behind the Testes, down to these.  

●●w Processes on the inside of the ●●edulla O●●ongata.  These long medullary Processes I never find wanting, though in different numbers, sometimes having seen three, sometimes two, and once I oould find but one, (though larger than ordinary) and constantly, in what number soever, ending in the transverse Processes at the aforementioned beginning of the fourth Ventricle.  
These long descending Processes are just over-against the Corpora Pyramidalia, on the other or under side of the Medulla Oblongata, and the transverse Processes at the beginning of the fourth Ventricle last mentioned, are a little above the original of the Eighth Pair of Nerves, insomuch that without being very circumspect one may mistake them for the original of that Nerve, whereas in reality I find them to be the original of the soft or hinder most Branch of the Seventh, as will be more particularly taken notice of hereafter, in the description of those Nerves; and therefore cannot but wonder how Dr. Willis (who speaks in one place as though he had seen them) came to assign them for the Root of the ninth Pair, 
Willls Cirib. Anat. p. 12. col. 2. per. 3.  beneath which and this Process I have always observed the space of half an inch.   

CHAP. XV. Of the Medulla Oblongata.  
THE third part of the Brain, in its general acceptation, according to the foregoing method, is called the Medulla Oblongata, all whose parts on its foreside having already been spoken of, it remains in the next place that we take notice of it on its other side, where are most considerable its Crura, 
Crura Medulla Oblongata.  so called, which Crura are only the under part of the Thalami Nervorum Opticorum before described, which in their Extremities becoming continuous to the under side of the medullary hinder part of the Brain, occasioned the Ancients to think the Medulla Oblongata had its foremost Roots immediately from the Brain there, as it had its hindermost from the Processes of the Cerebellum; but upon a more diligent enquiry it appears, that these Crura are more deeply immerged in and knit to the Medulla Globosa of the Brain forwardly, by virtue of the Corpora Striata, as also by the very medullary part of the Brain itself, which there, from the back or undermost winding part of the Corpus Callosum is perfectly mingled with it.  
Where these two Crura begin to come close together, the Protuberantia Annularis, 
FIG 6. BB  or Pons Varoliis, made up of the second Process of the Cerebellum aforementioned, gins to cover the Medulla Oblongata for about the space of an inch and an half, after which this Medulla Oblongata in one large Trunk is continued to the first Vertebra of the Spine, and so quite down to the end thereof.  
Whilst the Brain is in this position it may not be unseasonable to take notice of two fair white Bodies on this side of the Infundibulum, 
The two white Bodies behind the Insundibulum. FIG. 1. bb  in that depressed part of the Brain, where the Pia Mater (as hath before been taken notice of) is so remarkably double.  
There are also two white long medullary Processes called Corpora Pyramidalia both by Willis and Vieussenius, 
The Corpora Pyramidalia. FIG. 1. n.  which arise just at the ending of the Annular Process running down upon the Med. Oblongata the space of an inch, ending a good space below the place where the Eighth Pair of Nerves begin, which have their original between the Corpora Olivaria and the Chordal Processes partly on the other side thereof, contrary to the account we have of them by Dr. Willis, 
Willis, p. 13. col. 1. par. 1 p. 61. col. 2. par. 3.  who describes them as ending in pointed Extremities, just where those Nerves have their original.  
On each side of these appear plainly the Corpora Olivaria, 
The Corpara Olivaria. I●●d. o.  so called from their Figure, as the former were by Vieussenius, which with the Corpora Pyramidalia and two white Bodies behind the Infundibulum, he calls Conceptacula Spirituum Animalium, or places containing Animal Spirits upon several occasions of use to the Brain, both in its natural and intellectual Faculties.   

CHAP. XVI. Of the Nerves.  
IN the same position of the Brain we also have a sit time of taking a view of the Nerves, which are still medullary Productions of the Brain dispersed to all the parts of the Body, which have need of either Sense or Motion, and these are in number ten Pairs or Conjugations, having their Names and Originals as follows.  
The first is the Olfactory Pair, which after they leave the former Lobes of the Brain, and begin to run to the Bone called Ethmoides, take the name of Processus Mammillares; but this is chief in Brutes, where through their largeness they have that appearance, and are manifestly hollow.  
By the utmost Scrutiny I have been able to make, they have but one Original, and that is from the undermost and foremost part of the Crura Medulla Oblongata, where they advance on each side into the Globous medullary part of the Brain, from whence running concealed betwixt its foremost and hinder Lobes obliquely, for a good space, at last they come in sight, as you see them in the Figure: And by what means Vieussenius comes to find such diffused Originals for them as he speaks of, I know not.  
Their Use is known to most, and a particular account thereof, as of the rest, together with the manner of Sensation, with relation to the external Organs of Sense, is much more fit for a Physiological Tract than one of this kind.  
I shall therefore only at this time give a general description of the Nerves belonging to the Brain, how and where they arise, the difference or variety whereof serve very well to inform us, according to several late Theories, concerning the different Reservatories of the Animal Fluid or Spirits, and the different dispensation of the same to several parts of the Body.  
The second Pair are called the Optic or Seeing Nerves, 
The Second Pair. Ibid. 2 2.  of which I sinned no more Originals than of the former, and that is from those medullary parts called Thalami Nervorum Opticorum, tho' Vieussenius says they are from several parts; and Willis in general terms from the aforesaid Thalami Nervorum Opticorum, behind the Corpora Striata: which description is more exact in Quadrupeds, where the Thalami Nervorum Opticorum are altogether in situation behind the Corpora Striata, than in Men, where a great part of the Corpora Striata are situated on the outsides of the Thalami Nervorum Opticorum, and only their Heads or Extremities before them.  
The Blood vessels mentioned both by Willis and Vieussenius belonging to these Nerves, I have seen to run not only upon or with them, but also in injected Bodies exactly quite through the medullary substance of them, into the reticular Coat of the Eye, wherein they end in an infinite number of the most capillary Ramifications, which by an injection of that Artery made with Mercury, become very delightfully conspicuous to the Eye.  
The Nervous Fibres also, from the fifth and third Pair of Nerves, do twine about the Bodies of these Nerves, as the two abovementioned Authors do truly affirm, but how rightly they both assign to them the office of dilating and contracting them subserviently to the visory faculty, and preternaturally in Convulsions of the Eye, as though these Fibres were truly Muscles, or of the carnous kind, I refer to the Judgement of others.  
These go out of the Skull at its first Foramen.  
The third Pair arise out of the forward and upper part of the Annular Process, where 'tis contiguous to, and covered with the under part of the Thalami Nervorum Opticorum, coming out into sight from between them, just where that Process terminates forwardly, which is where the Crura Medulla Oblongata come together into one body, constituting the Caudex Medulloe Oblongatoe.  
These running through a duplicature of the Dura Mater, on the outside of the Circular Sinus, go out of the second hole of the Skull to the Eyes, and are therefore called Par Oculorum Motorium, to the voluntary motion of which only they are granted to be subservient, which, seeing they have their original from the Cerebellum, afford us no weak Argument against the Hypothesis of Dr. Willis, who hath reserved that part in Nerves subservient to involuntary motions only.  
The fourth Pair is very small, 
The Fourth Pair. Ibid 4 4.  coming from the transverse Process on the foreside of the Medulla Oblongata behind the Testes, first coming in sight between the undermost part of the hinder Lobe of the Brain and the Cerebellum laterally, crossing that part where the Annular Process ends towards the Crura Medulla Oblongata, from whence they pass into a duplicature of the Dura Mater, and afterwards, a little more outwardly than the former, goes through the same second hole to the Trochlear Muscle of the Eye, and are called from their moving of that according to the passions of the Mind; the Pathetic Pair.  
The fifth Pair is broad and large, 
The Fifth Pair. ●ld. 5 5.  made up of many thick Fibres continuous to each other, some softer than others, arising from the uppermost part of the Processus Annularis, which is backward laterally, where 'tis broadest, by reason of the second Process of the Cerebellum there entering it.  
This Nerve, 
The several ●●●ches of the fifth Pair.  after having first climbed over the inner Process of the Os Petrosum into a kind of a Cavity made of a duplicature of the Dura Mater in that place, immediately swells into a kind of a thickness, called a Ganglion, 
Pro. 3. B  from whence several Branches are propagated, lying betwixt the Dura Mater and the Cranium, on each side the Sella Turcica, without any Fovea or Cavity at all, going out of the Skull at three several place, 
Pro. 3. C, D, E  its superior small Branch at the second hole with the third and fourth Pair of Nerves, its inferior smaller Branch at the third hole, and its posteriour or largest Branch at the fifth.  
From the inside of the foremost Branch two little ones turn back, 
FIG. 2. y.  and meeting with another small Branch a little lower turned back also from the sixth Pair, where that Nerve is fastened to the outmost or borrowed Coat of the Carotid Artery, make up a small Trunk of a reddish or fleshy colour, like to that which 'tis of when passed out of the Cranium, (as Veslingius hath truly observed, 
The Intercostal Pair. X. Z Z.  who calls it The Internal Branch of the Sixth pair) which descending obliquely, and creeping under that Artery, betwixt its external, proper, and borrowed Coat, goes out with the Carotid Artery at the fourth hole of the Skull, which is in a manner double between the Os Petrosum and Cuneiforme, and from its passage through the Thorax, near the Roots of the Ribs, (all-along which, it receives a Branch from the Intercostal Nerves) is called, The Intercostal Pair.  
The sixth are about the bigness of the third, 
The sixth Pair. FIG. 1st. 6 6.  arising from the hinder part of the Annular Frocess over-against, and not far off from the beginning or head of the Corpora Pyramidalia. It sends out sometimes one (in this Subject very short) sometimes two slips, as was afore said, for the making up the Trunk of the Intercostal Nerve, and after that (with the foremost Branch of the fifth Pair, in one and the same duplicature of the Dura Mater, together with the preceding third and fourth Pair of Nerves) goes out at the second hole of the Skull, and terminates in the abductory Muscles of the Eye.  
The seventh Pair, 
The seventh Pair. Pro. 1st, 7 7.  or Hearing Nerve is large, and comes out almost just over-against the original of the fifth Pair, on the lower or under side of the second Process of the Cerebellum, where it first appears coming out from the Cerebellum to make the aforesaid Protuberantia Annularis between the Corpus Olivare and that Protuberance, as though it crept out betwixt them, and had (as it really hath) a move remote extraction.  
It consists of two distinct Processes, the first of which is more round, hard, and less than the second, that being for Motion, this for Sense, but tho' they seem as though they had the same original, being seemingly continuous at their rise from the Brain, 
Willis, p. 12 col. 2. part 3 & p. 56. col. 1. par. ●.  (which Dr. Willis affirms they have, tho' sometimes he makes it in one place, and sometimes in another) yet upon a further enquiry it does appear otherwise, the first or hardest having its original from the Caudex Medullaris, not far from the place where it comes first in view; the second very remote from the transverse Process or Processes in the passage to the fourth Ventricle before described, 
FIG. 7. two  (which in another place the same Author seems plainly to have observed, 
Willis, p. 78. col. 1. par. 2  taking it for the Original of the other Process of this Nerve;) from whence it ascends all-along on the sides of the Medulla Oblongata till it arrives at the aforementioned place, where it first, together with the other Branch, leaves the Medulla, to pass out of it at the seventh hole in the Bone called Petrosum.  
The eighth, 
The eighth Pair. FIG. 1st 8 8  or Par Vagum, arises a very little beneath the seventh, but yet not from any part of the Annular Protuberance, but exactly in that somewhat hollow place betwixt the Corpus Olivare and third or Chordal Process, having numerous (I have counted ten or twelve) Fibres, but all continuous at their first rise, for its original.  
This in a multitude of Ramifications is spent upon the Bowels, and goes out at the eighth hole with the Spinal Accessary Nerve, where the great lateral and the inferior little Sinus' in the Basis of the Skull go out into the Internal Jugular.  
To this eighth Pair about half an inch from its first rise, whilst it climbs upon or sticks to the Pia Mater upon the Basis of the Cerebellum, ascends a Nerve called Spinalis Accessorius by Willis, 
I●id **  but long before him taken notice of, nay, painted and described, by Vidus Vidius, 
Vidus Vidius, p. 93. T. 18. Fig. 2. *  the original whereof I find to be as far as the seventh Vertebral Pair, from the foremost and hindermost beginnings of that Nerve, notwithstanding Vieussenius confines its original to the fourth Pair of that part only.  
This Nerve runs under the Vertebral Artery near half an inch on the side of the Medulla Oblongata, at length, about half an inch from the beginning of the eighth Pair, leaves the aforesaid Medulla Oblongata, running obliquely upon the Pia Mater of the Cerebellum, to join with the aforesaid Pair, which it really does in that very place, though it part with it afterwards again.  
The ninth hath several (in one Body I counted seven or eight) pretty large Fibres for its original, 
The ninth Pair. Ibid. 9 9  very distant one from another, the first of them coming higher, from the very top of the Corp. Olivare; the next, and several others, are much less, a quarter of an inch lower; and the last much lower yet, about the ending of the Corpus Olivare, or beginning of the tenth Pair, with several others between the Pia Mater and subjacent Medulla Oblongata; but after all, its Trunk is very little, about the bigness of the Accessary Pair.  
Through the Fibres of this Nerve there runs commonly a small but very visible Branch of the Vertebral Artery, at its original; as you see in the Figure expressed by the Letter k on the right side, 
P●o. 1. k.  going out at the ninth hole, together with this Nerve and the Vertebral Vein, 
Vieus. p. 163  which Vein Vieussenius mistakenly makes to go out at a tenth hole, forasmuch as that is never found in Nature, neither need be, seeing the tenth Pair goes out at the last or great Foramen, by which the Medulla Oblongata passes into the Spine.  
The tenth Pair, 
The tenth Pair. I●id. 10 10  (which had it a double Original from each side of the Spinal Marrow, (as all the rest of the Spinal Nerves have) might much more properly be called the first Vertebral, inasmuch as that both a great part of its rise and egress is quite out of the bounds of the Cranium) serving chief the Muscles of the Neck, it gins with three, and sometimes more, small Fibres lower a great deal, out of the Medulla Oblongata, almost an inch below the Trunk of the ninth Pair, and is about the size thereof.  
It goes out of the Cranium betwixt the first and second Vertebra of the Neck, making its passage through the Dura Mater from the Medulla Oblongata, about half an inch below the place where the said Artery comes in.  
The Structure of these Nerves is consistent of many Fibrillas or Stria's, a certain number whereof being first enclosed in a production of that delicate inward Lamina of the Pia Mater afore described and spoken of, makes up a Fasciculus or Bundle, and many of these colletively the Body of a Nerve.  
In these Fibrillas or Stria's (betubulous and always turgid, as in so many Rivulets springing from the main Fountain the Brain, and from thence distributed to every respective part of the Body) is contained the Animal Fluid, by means whereof there is maintained a constant intercourse betwixt it and the Soul, and reciprocal acts of Friendship betwixt one part and another.  
This Animal Fluid I look upon only as a Body consisting of very minute and flexile Particles, contained in such a space as allows them a capacity of being agitated on all sides by virtue of the subtle matter, or Aethereal Globuli they swim in, by which means they are rendered capable of pervading the narrowest Channels of the whole Machine, provided its Orifice or Poor be adapt thereto, in contradistinction to those other sort of grosser Particles of Matter, which by reason of the narrowness and figure of the space they are to enter, do approximate so close, as to become contiguous in all their Superficies, whereby they become deprived of their former expansive agitation, which is always necessary to make a Body fluid, and like so many small Filaments orderly disposed, do constitute the Enclosures or Coats of those Vessels the Fluids are contained in.  
This Animal Fluid I conceive to be in a continual state of Transpiration, proportionable to the measure of its leisurely production, seeing no more necessity of ascribing any further Uses to it, besides those aforementioned, than I do to the watery Humour of the Eye, besides its service to Vision, which is always in a state of fresh production, as by the Excellent Nuck's Experiment is plainly manifest; 
Nuck de Saliv. & Duc. Aqu. Oculor. p. 109.  and yet, by virtue of Transpiration, some way or other, though to us not visible, without any inconveniency to that noble Organ.   

CHAP. XVII. Of Sensation and Motion in general.  
THE Nerves thus constituted, become accommodated for Use in relation to their several and distinct Functions, in some consisting of Sense only, such as are those appertaining to the particular Sensories, (viz.) the Smelling and Seeing Nerves, as also the soft Process of the Hearing Nerve, some Branches of the fifth, and it may be of the ninth Pair, for Tasting; in short, all the Nerves belonging to those external Sensories, by way of eminency, and in a less eminent or general way all the Nerves of the whole Body, which are distributed to such Parts as by reason of their structure are capable of Sensation only, any of which, as furnished with the Nervous Fibrils, but more eminently the Cuticula, my properly be called an Organ or Sensory of Feeling; in others of Motion chief, such as are all the whole System of Nerves, (excepting them only aforementioned) says, which though in a less eminent manner, are nevertheless sensitive Nerves also: In others of both, in all respects (viz.) either in a more eminent or less eminent Sensation, and Motion too, with relation to the different Fibres they consist of in their Originals, as the fifth and ninth Pairs.  
These two different Functions of Sensation and Motion are executed after two as different manners.  
The first of which, being occasioned from external Objects, is discharged by a pressure thereof made on the Instrument of Sense, so that the Motion is backward irom one Extreme of the Organ to the other, where it terminates in the Commune Sensorium, commonly so called, and is therefore styled Perception, Passion, or Affection.  
The other is discharged by some manner of impulse upon the Organ from within outwardly, with a tendency either to acquire some Good, or avoid some Evil; by which Impulse, when carried on so far, either in a natural or moral sense, as to terminate in, or to be executed upon its proper Object; the Object than may be said to suffer as before in the other case it might be said to act, and the perceptive Faculty now to act as before it might be said to suffer, and this Action is commonly called Local Motion.  
For whose sake, seeing 'tis of different kinds, learned Men have thought sit to organize or divide the Brain into two distinct Provinces invested with several Rights and Jurisdictions abating the Power of the Sensitive Soul, which before was looked upon universal over the whole Brain, allowing it only a principal, but no absolute Empire there: And this they have done upon no weak or unreasonable grounds, seeing that Local Motion is not only in many respects performed without its assistance, but even against its power of resistance; as in the Pulsation of the Heart, vermicular Motion of the Bowels, and in a great measure the Act of Respiration.  
Now, that which hath been taken from the Brain hath been conferred on the Cerebellum, to which, though some Power in this Affair may justly be allowed, as was before observed, yet possibly not altogether so much as there hath been.  
Dr. Willis, who is Chief in this Cause, having distinguished Motion into voluntary and involuntary only, hath made the Cerebrum accountable for the one, and the Cerebellum chief for the other; and to that end hath furnished it with the like number of Nerves, as in his own words is expressed, 
Willis c. 1●.  Vt divisum cum ipso (i. e.) Cerebro, imperium Cerebellum habeat; nay, considering the Intercostal Pair, derived from the fifth and sixth Pair, which belong to the Cerebellum, he hath made it exceed.  
I am apt to think that Learned Person too soon fell in love with his first Thoughts, the ordinary reason of either one's seeing false, or not far enough.  
Nothing being more apparent, than that most of those Actions of Animal Motions he calls Involuntary, and of which he gives so many Instances, are equally found in Brutes and rational Creatures too, whilst in the state of Infancy, as well as when grown up with this only difference, that all of them in the last are under the controlling power of the Soul, and consequently may be suspended upon a reflexed Act of the Understanding; whereas in Brutes and Infants they are necessary, and do as naturally ensue upon the impulse of the Object, as Water, when unconfined, runs towards a Plain.  
Now, if all these were supposed to be under the power of the Cerebellum only in Brutes and Infants, the Brain itself must necessarily be thought altogether useless in them.  
It will be necessary therefore to take notice, that there are two sorts of Animal Motion in Brutes, as in Rational Creatures, the one purely natural, such as is Pulsation of the Heart, and various contraction of the Viscera, proceeding from a certain portion of the Animal Fluid continually dispensed to the Nerves in an equal proportion, and so may be said to have their cause originally co-existent with the Creature, and always present: And this kind we find by a most convincing Experiment hereafter to be mentioned, to be from the Cerebellum, and absolutely free from the dominion of the Brain, in its ordinary way of acting or influx.  
The other is that of Instinct, relating to the Sensative Soul, or an aptitude of the Nervous Structure, to act according to the Impressions made upon the Nerves, either from within, or from without, and so may be said to depend on the presence of such Causes as are supervenient and extraneous to Nature, suitable to the impressions whereof the Animal either pursues or avoids the Object, obeys, or resists the Impulse.  
Now, I take it for granted, that no body will deny but that the Nerves (by virtue whereof these last actions of Instinct are performed) whether th●y ●r●se from the Cerebrum of Cerebellum, are equally under the command of the Soul; or else, as I said before, the Brain in those Creatures is to no purpose.  
And of this sort I reckon all those actions in rational creatures of Instinct before they have attained to the use of their Understanding, from any sort of Impressions, or inadvertent and inconsulted, when he hath the controlling power of Reason allowed him and makes no use of it, such as are called Habitual, which at first were produced by command of the Rational Part only, but through frequent repetitions at last, without any command from that, out of a blind obedience to a bare impulse from the Object; or lastly, such as happen when he hath altogether lost the use of it, as in Sleep or Distraction; in which last Cases 'twill be very difficult to distinguish him from a mere Machine or Automaton.  
Now, from what hath been said, I cannot but think it plain, that many of the Actions before spoken of in Dr. Willis's sense, by him called Involuntary, as proceeding from the dominion of the Cerebellum only, such as he calls the various Configuration of the Face, from some Impulse or Provocations in the Viscera or elsewhere, erecting the Ears, turning the Neck and Eyes about, sudden Shrieks and Outcries upon some extraordinary frightful Object surprisingly affecting one Sense or another, furnished with either such Nerves as he supposes to be altogether under the command of the Cerebellum, as the fifth and seventh, or else to have a very near correspondence with that part by virtue of Vicinity, as the ninth, do more truly proceed from that perceptive faculty, or (to use his own words) that part of the Soul, he hath confined to that part of the Medullary System called the Cerebrum. inasmuch as in reasonable Creatures they may and commonly are suspended, as well as the Nerves they slow from, sometimes made use of as Instruments of Voluntary Motion by it also; and to think the contrary, is as much as to say, that when any body happens to express any of the aforementioned involuntary Acts, or but hit his Bedfellow a box of the Ear, whilst asleep, all these must be allowed to proceed only from the Organ of Involuntary Motions called the Cerebellum.  
And of this kind also in a great measure I reckon Respiration, concerning which I cannot easily be brought to think it satisfactorily explained by Dr. Willis, from the Energy of those Animal Spirits which flow only from the Cerebellum in the Par Vagum, after the same manner they do to the Heart by the Intercostal and that Pair for its pulsation, and as only under the command of the Soul, to be stopped now and then, as it pleases, by virtue of some Nerves communicated to the Intercostal Muscles and Diaphragm, the chief Instruments of breathing, from the Spina Dorsi.  
I am therefore rather inclined to think this Motion is of the other different kind before spoken of, under the Title of Instinct, proceeding from an extraneous supervenient Cause, acting conformably to the course of Nature in other Cases of the same kind, as in Hunger and Thirst, and the like, where the obtaining the designed End or Effect renders the part from whence comes the Motion for some time insensible of the impression, and where, after the▪ ceasing of the Effect or Motion, the sense of the impression revives again, whence there happens an equal reciprocation between the Sense and Fruition, or Sense and Motion.  
To apply this account of the manner and reason of the Spirits acting upon the Stomach and Par●●te in relation to Hunger and Thirst, to that of the Systole and Diastole of the Lungs or Respiration, 'twill be needful to take notice, that in an Infant unborn there is no Respiration, but yet there is a Cerebellum; and that if this sort of Motion called Instinct, which I make to differ from purely Natural Motions, such as are contemporary with even the first living Rudiments of the Individual, was altogether and solely owing to the Cerebellum, after the manner of that of the Heart; then of necessity the Child in the Womb ought to respire. But being satisfied of the contrary, it remains that we account for its respiration another way, which is as afore noted, through the presence or absence of the first moving Cause or Impulse, which I make or suppose to be any thing impressing the Nerves, propagated through the Organs of Breathing, so as to transmit the impression from within to the perceptive Faculty, presiding both over the Cerebrum and Cerebellum too, to the end the Spirits may from thence forthwith be commanded into such other Nerves as act those Muscles which serve for enlarging the whole Cavity of the Thorax, in order to let the Air into the Lungs more plentifully, which was the thing aimed at by Nature; and these are the Intercostal Muscles and Diaphragm.  
Now 'tis easy to conceive, that whilst the Child is enclosed in its Mother's Belly, there is not that occasion for Respiration as when 'tis born, the main Stream of Blood all that while finding no passage through them, and that which does by the Ruyshian Artery made of Juices much more mild and cooler, the native heat being little, and the Aliment mere Chyle or Milk; from whence it falls out that the Pulmoni●k Nerves go altogether unprovoked, which after birth are continually otherwise impressed or provoked by the hot Effluviums of Blood, new bred of stronger Food, and by a stronger native heat, and wholly flowing through them; which heat continually, as the Child acquires a greater maturity, increasing, may, for aught I know, not a little contribute, by way of natural impulse, to its exclusion.  
The truth of this will the more clearly appear to any who will take the pains to consider well of the structure of Parts in Children unborn, in whom the usual circuit of Blood through the Lungs, which are designed for rarifying and perfecting the mixture of Blood and Chyle, is denied; as also through the Liver, serving chief for separating that gross Excrement the Gall, not bred (at least in any proportion) in an Infant unborn, and in lieu of these, other Passages, (which become altogether unnecessary after birth) provided by Nature after a shorter and more compendious way, (viz) by the Foramen Ovale betwixt the Vena Cava and Vena Pulmon. and Tubulus Arteriosus between the Art. Pulm. and Aorta in the Lungs, and the Tubulus Venosus between the Sinus of the Porta and the Cava in the Liver; as hath been most sagaciously observed by the late Learned Dr. Walter Needham.  
'Tis true, That in several Creatures there are some Nerves very much depending on the Cerebellum, as are they which minister (though in a different manner, as hath already been taken notice of, and will be hereafter further explained) to the Natural and Vital Functions, (viz.) the Par Vagum and Intercostal Pairs, and therefore the aforesaid Author, who is in this as in many other of his Discoveries very fortunate, and highly commendable, made a very good guess when he brought these Faculties into subjection to that part, inasmuch as by several others, as well as by my own Experience upon living Bodies, we find, that notwithstanding most part of the Brain be pared off with a Razor, yea, even after the Medulla Oblongata be divided betwixt the Cerebum and Cerebellum, and taken wholly out of the Cranium, the Heart will beat, when at the same time if the Cerebellum itself be but cut in pieces, though all the rest of the Brain be kept entire, the Creature expires presently.  
Yea, I have seen Respiration (which only in part depends on the Cerebellum) totally to cease upon only a sudden violent compression of that part by a blow, and, after its being wounded, the Heart to cease beating immediately.  
All which must of natural consequence fall out upon the Hypothesis, That those Functions of Nature do depend on the Cerebellum for their source and influence, which is constant, uninterrupted, and out of the arbitrary jurisdiction of the Brain; yet with this difference, that in Motions purely natural, and either contemporary with the Embryo, as the first signs of its vitality, such as is Pulsation of the Heart, during its enclosure within the Mother, or supervenient upon its further growth and more visible organisation of Parts, as the natural contraction of the other Viscera subservient to the offices of Protrusion of the Chyle, separation of the Glandular Juices, and proscription of the Excrements, the Animal Fluid or Spirits do altogether flow from the Cerebellum, the Nerves there both descending from the Cerebellum, and terminating in those parts aforementioned; whereas in Respiration, which I call a Motion of Supervenient Instinct, (if I may be allowed to use the word Instinct in that sense) the Nerves descending from the Cerebellum, and propagated through the Lungs from the Par Vagum, serve only to convey the first Impulse or Impression of the Object to those parts which are by Nature framed and qualified to produce Respiratory Motion, and those are the Nerves of the Spinal Marrow, receiving the impression from the Cerebellum, seeing that by the aforesaid Experiment it appears plain, that after the whole Cerebrum was divided from the Cerebellum and Medulla Oblongata, the act of Respiration continued for a considerable time entrire, which Motion is dependent on the Sensative Faculty presiding in the Cerebellum, transmitting the first Impulse produced by the eighth Pair or ParVagum (as before observed) and communicated thence to those Spinal Nerves which act the Intercostal Muscles and Diaphragm.  
So that all the office of the Par Vagum, which is propagated through the Lungs, is to convey the Impression from thence to the Cerebellum, which by virtue of its connexion with the Caudex Medullaris (from whence the Ancients rightly thought that part had its hindermost Roots from the Cerebellum, as before taken notice of) it is able to transmit it further, as the Sensative Faculty presiding there shall direct, and that too by the common way, the Medulla Oblongata and Spinal Nerves.  
And further; That this part is as capable thereof as the Cerebrum, and is not wholly and only deputed for the service of such Nerves or Organs as are employed by the involuntary part or portion of the Soul, (as Dr. Willis would have it) appears in that the third Pair of Nerves, by him allowed to be amongst the number of the other kind of Nerves, (viz.) those commanded by the Will, from hence (as hath been already shown) hath its original. And here also furthermore give me leave to add, by way of conjecture, that the reason why the Soul hath not an equal command over those afore mentioned Nerves dedicated to the vital and natural Motions, is, the early date or commencement of the office of those Nerves, by which means they contract an habitual irresistible Influx, much less so in those belonging to the Respiratory Functions, the exercise whereof is of a later date; and lastly, the Influx is not in the least so habitual in those other subservient to the Organical Functions of the Limbs, inasmuch as they are not capable of being exercised till a much longer time after, and then not so uninterruptedly as either the first or the second, but gradually, and with intermissions.  
So that the only reason why upon cutting the Cerebellum Respiration ceases, is, that by that means its structure is discomposed, and rendered unfit either to receive or transmit the impression further to the aforesaid Nerves, which are subservient to the Instruments of Respiration.  
'Tis true, there are reciprocal communications betwixt the Nerves of the Intercostal Pair, Vertebrae, and Diaphragm, yet seeing they terminate nor immediately in the Parts of each others particular distinct jurisdictions, there is no interchangeable act or office from thence produced betwixt them.  
For as, notwithstanding▪ there are so many Branches of Nerves communicated from the Spinal Nerves subservient to voluntary motion, to the Intercostal Pair, on their descent to the Viscera, and yet by reason of their not terminating in those parts, they are not in the least able to bring these Nerves under the commands of the Rational Soul, by which provident Care of Nature it so falls out, that 'tis not in the power of any, by misguided Reason, to act injuriously to themselves: So by virtue of several Branches reciprocally communicated from the Intercostal Pair in its passage down to the Viscera, to the Spinal Nerves, there is no power given to them of moving the Muscles to which they are subservient uninterruptedly, after the mere manner of the Viscera.  
But now, to return to where we left off, in some Creatures it's very plain, that Nature hath extended this imperial residence of the Soul beyond the Cerebellum, even as far as the Spinalis Medulla, having not only put this last motion, but that of Pulsation too, under the jurisdiction of that elongation of the Brain; as appears in the famous Experiment of the Industrious Caldesi upon the Tortoise, which after the Head was cut off lived, and carried its Shell about, the space of six Months.  
Besides which, 'tis remarkable, (by way of digression) according to another Experiment by the aforesaid Author made upon that Creature, that after even the Heart and all the Viscera besides, were taken out, except the Lungs, that Creature (to use his own Expression) was sound so to resist Death, as to turn itself from the inverted or supine position it had been placed in, in order to make the Experiment, to its prone or natural one, and to live and move six hours, after. From whence it appears, that Muscular Motion is capable of being performed by the Animal Fluid alone, without the concurrence of the Blood, by most Authors constantly hitherto made to go a share therewith in the performance of that action. 
Caldesi, p. 75, 76.   
So that we find Nature hath not stinted itself to one place for the Seat of the Sensative Soul, or Reservatories of the Animal Spirits so called, in order to the discharge of the aforementioned Functions, no more than it is at a loss about the maintaining them in their Integrity by other ways, when it hath so fallen out that the natural structure of the Organs, destined by Nature to that end, have utterly been destroyed, of which we have many Instances in the Anatomical History, those Functions in several Creatures remaining perfect, where after death there have been sound neither any Cerebrum or Cerebellum at all, or at least such as by their constitution was utterly rendered useless to any such end.  
Of the first is an Instance of the Learned Wepfer, in a Child living sixteen hours alter it was born, and discharging all the Duties of Nature that one of its age was capable of, and by though by (which all the patrons of a nutritious Juice by the Nerves may do well to take notice of) of a very strong and good habit of Body, 
Misc Caries. Au. 3 p. 120  whose Brain, after death, was found to be only an heap of Watery Bladders or Hydatides, except a small part at the bottom of the Skull, lying in a Sinus made in the Wedglike Bone, where the Pituitary Gland is commonly found consisting only of three Medullary Bodies, two of which being each of the bigness of a Kidney Bean, and the third behind them of a Pea only, from which indeed there did proceed some, but very inconsiderable Nerves, or Nervous Fibrils, but such as none can judge of a due proportion requisite to satisfy the Exigencies of the common natural, and vital Functions.  
The truth of which is still more plain, and without exception, in another Instance in the Miscell. Med. Physic. Gallic. of a Child living sieve days after it was born, 
Misc. Med. Phys. Gall. Au. 3. p. 54.  whose Head had nothing but Water contained within the enclosures of the Dura and Pia Mater, without the least footsteps of any medullary part at all.  
Parallel to which two last Instances, I had one communicated to me by that curious Anatomist and learned Person Dr. Tyson, in a Child born alive, with no more Brain in the Skull than what might lie in a Filbird-shell, the Medulla Spinalis being much larger than ordinary, as though part of the absent Brain had been squeezed down thither.  
Of the last (viz. where the natural conformation hath been depraved) there is extant an Instance in two several places of the Miscell. Curios. in a sat Ox, 
Misc. Cur. Obs. 26. & 130. An. 1.  which while living there were observed but very little signs of any such thing, whole Brain was nevertheless after death found wholly petrified.  
From all these 'tis manifest the Sensative Faculty is able to answer its internal or external Impressions, by one part as well as another, and that the Medullary System of the Spinalis Medulla may become as adequate a Sensory, in relation to the aforesaid Functions sometimes, as either Cerebrum or Cerebellum.  
And as to the power or influence the Soul in general exercises over the Nerves, howsoever different in their original, seeing we have already observed what a provident care Nature hath taken for the preserving Creatures from their own violence, in that it hath not only constituted the chief Fountain from whence the great current of Spirits is derived, for the service of the vital and natural parts, by the Eighth and Intercostal Nerves, which is the Cerebellum, so as to be free from the commands of the Rational Will in its ordinary way of acting, but hath also taken care that not any of those Branches which have their originals from Trunks, which are under the power of voluntary dictates of the Soul, should terminate in such Organs by which those Functions are discharged, (abare communication between Nerves of different Provinces not being sufficient to such ends or offices, as hath been observed in those aforementioned additional subsidiary smaller Streams of Spirits flowing to the parts consecrate to the natural and vital Functions by Branches propagated from the Spinal Marrow, to the Intercostal Nerve, all the way of its descent to the lower Venture.)  
So we may further also remark, that as there are some manner of Impressions made upon the perceptive Faculty, after such sort of a manner as that it even loses its power over its own Subjects, (viz.) the Nerves, which are subservient to its voluntary commands, as in Laughing, Sneezing, and libidinous Erections, the Organs by which these Actions are produced, being altogether under the power of those Nerves subservient to the voluntary dictates of the Soul, and acted after the very same manner as those of Respiration, as often as preportionable objects present, and (notwithstanding the assertion of Dr. Willis to the contrary, who makes Laughing proper to Man only, and, by the authority of Aristotle, Sneezing an Affection proper but to few, if any other Creature besides Man) might also produce the same effects in Brutes, 
Will p 106  provided their stupid Souls were capable of being equally impressed by such Objects as are proper for exciting a rational Laughter, as we see they are by those producing the aforementioned venereous actions, of the want of the Plexus Cervicalis, of the Intercostal Nerves, and two or three small Branches propagated from thence to the Nerve of the Diaphragm (which he calls a Disposition peculiar to Man, and consequently in his opinion the cause of that Affection in him) might be in a great measure supplied not only by that nervous Branch we find propagated from the interior Plexus of the Par Vagum (which Nerve is equally dependent on the Cerebellum, as the Intercostal) to the third Brachial Nerve, from which the Nerve of the Diaphragm hath one of its originals, but also that other propagated from the Thoracick Plexus of the Intercostal Nerve itself, to the same aforesaid Brachial Nerve, into which the Nerve of the Diaphragm is inserted.  
So, on the contrary, there are some Impressions made upon the Soul sometimes, through which it acquires a power over those Nerves at other times in no wise subject to it, and those are the impressions either of great Joy or great Grief, suitable to which the Vital and Natural Faculties are made either much more or else so much less vigorous than ordinary, as even quite to languish.  
How this comes to pass, according to Dr. Willis in savour of his own Hypothesis, and particularly in relation to the first, (which allows of no Involuntary Motions, but what come from the Province of the Cerebellum) is explained by supposing an undulating or rolling motion of the first impression upon the Brain out of it again, through the Natiform Processes into the Cerebellum, and from thence by the Annular Process into the Intercostal Pair of Nerves, and so to the Nerve of the Diaphragm, (and he should, to make this way of explication entire, have taken in also all those Vertebral Branches inserted into the Intercostal Nerve, in order to the moving of the Intercostal Muscles, without which that action cannot be performed) by a correspondence between which Nerves and those of the Face, being all of one family, the aforesaid Gesture of Laughing is performed.  
Now, besides the needlesness of bringing the Conceptions or Impressions of the Brain under a necessity of being executed by the inferior Province of the Cerebellum, till such time as 'tis proved, that such motions of the Spirits, upon extraordinary occasions, may rationally be granted, without supposing a regular motion of the same through such supposed Passages leading from one Part to the other at all other times, (the allowing whereof does necessarily imply a capacity of the Soul to alter the course of the Spirits influencing the vital and natural Organs, at least in some measure, at its pleasure, which is plainly contrary to Experience;) I shall hardly look upon that Hypothesis to be any more than merely precarious.  
And further, to show, that such Effects or Alterations of the Vital Organs happening upon violent Passions of the Mind, are no way owing to such a transmission of the Animal Fluid from the Cerebrum to the Cerebellum, as the aforesaid Author supposeth, I ask, how it should come to pass that in the contrary Passion of Grief, especially when occasioned by surprising frightful Accidents, the Heart should so languish, as sometimes wholly to cease beating, seeing in the aforesaid Experiment we find that Motion self-sufficient, by virtue of a constant irradiation or influence of the Cerebellum only, and consequently could not be thought so to languish upon such occasions for want of those Spirits it never stood in need of.  
Without therefore being forced to have recourse to that other Hypothesis clogged with so many difficulties, I think the aforesaid case may admit of another manner of explication, consistent with what I have all-along advanced upon this Subject relating to the true source of voluntary and involuntary Actions: if we suppose, that from such Impressions upon the Soul as are either extremely more or less welcome to it, (in which case the Object is said to act unproportionably upon the Subject) it may not only act accordingly, above its usual irradiation and force over the Cerebellum, and by that means, as sending the Spirits either more or less copiously to the Vital Organs, particularly the Heart, the nearest way, (viz.) by the Par Vagum and Intercostal Pair, for that time render them more vigorous, or more languid in their operations, in proportion to the difference of the Passions, just after the manner it happens in cases of Alienation of Mind or Distraction, where by the Strength of the Impression, or Idea upon the Mind, it drives the Spirits with such an impetus into the Limbs, as makes them act with a vast greater force than what they were wont to do, even above the resistance of Chains or Bars of Iron; but also it may transmit the Spirits more or less copiously, to the Vital and Natural Faculties, the other way freed from the subsidiary Nerves of the Spina aforementioned, to the Intercostal Pair, which sends forth ramifications to the Heart (in Men especially) equally with, if not more plentifully than the Par Vagum, and from the Vertebral and Brachial to the Nerve of the Diaphragm and Intercostal Muscles, by which means it so falls out, upon such impressions, that the Organs of Respiration to the sight, and that of Pulsation to the touch, are very remarkably affected.  
By this means I have endeavoured to restore the Brain to a capacity of putting its own Conceptions or Impressions made upon it into execution, without being beholden to its neighbour the Cerebellum, and that either in relation to its voluntary, inadvertent, or involuntary Acts; where, note, I make a distinction between Acts involuntary and those of inadvertency, inasmuch as these last, though they are not with, yet they are not contrary to the actual consent of the Will, after the manner of the natural actions of the Viscera, such as are out of the power of the Will to hinder; besides which, I look upon no other in Rational Creatures (in a strict sense considered) to be involuntary, forasmuch as 'tis a contradiction to say a Voluntary Agent does any thing against his Rational Will (though it may be against his Approbation) by which he is only distinguished from a Brute: Though Dr. Willis hath all-along used the word involuntario in another sense, confounding it with acts of mere Ignorance under the term of Insciè, and those also done only inadvertently, or without consideration, under the term of Inconsulto; and doubtless upon this notion of Involuntary Motions built his Hypothesis, which makes all those Actions which are performed at any time without the notice of the Intellectual Faculty, notwithstanding at other times they are altogether under its command, equally depending on the Cerebellum as those purely natural, which are always free from the power of the first, and also absolutely subject to the last.  
These Actions I have therefore called by the term of Supervenient Instinct, and being the mere Effect of external or internal Impressions upon Sensative Bodies, as Echoes are to those upon such as are only natural, are equally competent to Rational and Irrational Creatures, and capable of being exerted by the influence of the very same Nerves which minister to the Sensative Faculty, whether it act advertently or inadvertently in the one, or spontaneously in the other, (where, by the way, it may not be altogether unworthy of our taking notice, the genuine sense of that word in Actions performed by those Creatures, is much nearer akin to the term Inconsulto than Involuntario in Men) without the supposed rambling Motions of Impressions made upon it, (through Passages only at some times or upon eztraordinary occasions made use of) out of the Cerebrum into the Cerebellum.  
Now, as to the organisation of this Part, made to consist of various Medullary Prominencies, Appendices, and Tracts, by Nature contrived for and adjusted to the various functions of the Soul, and dispensation of the Animal Spirits through the whole System of the Nerves, which first are confined to, or made to reside in such and such places as so many distinct apartments, viz. the Commune Sensorium in one place, the Imagination and Judgement in another, and the Memory in a third; of which there is such a large and formal apparatus and description (tho' with great discrepancy of opinion) in Willis and Vieussenius, the one placing the Commune Sensorium in his Corpora Striata only, the other in the superior and middle Corpora Striata, jointly with the Centrum Ovale; from both whom Des Cartes and several others, and with much more show of Reason, particularly Malpighius, differ, 
Malpig. de Cereb. p 11. par. 2.  placing it in the extreme limits of the medullary part of the Brain, where 'tis continuous with the cineritious circumassused Part; I must confess, that as I have not been able, by the best enquiry I could make either into Brains dissected whilst fresh, or when boiled in Oil, to discover any such actual configuration or disposition of Parts, as we find so formally delineated by either of them, but especially the last.  
So neither do I see any necessity thereof, seeing we may much more easily, and to the selfsame ends and advantages, look upon the Soul as one internal principal Sensative Faculty. and the whole medullary part of the Brain, as consisting of such Fibrils or Vascula's as in some places more nearly in others more remotely communicate with the Nerves propagated thence to all the external Sensories, one adequate Common Sensory, by which that principal Faculty both receives all its impressions, and accordingly, as by so many gradations of one and the same power, executes or performs those different Functions commonly going under the aforesaid Names of The Common Sense, or Simple Apprehension, Imagination, Judgement, and Memory.  
And as to the second, (viz.) the Medullary Tracts, by which the Animal Fluid, as by so many Rivulets, is derived from the great Pond or Magazine into many Rivers, furnishing the whole Body therewith, all I could find by the most diligent search, were only those which have already in the preceding Sheets been remarked, of which, in the first place, are those in the Corpora Striata, very large and discernible.  
Those in the inward or concave Superficies of the Corpus Callosum running transversely by the Septum Lucidum into the Fornix, and from that longitudinally into its hinder Thighs or Pillars formerly called Bombyces, over which they run in a wreathed manner, as was before observed, terminating in the back part of the Lateral Ventricles, enclosed in the hinder Limbs of the Brain, which Ventricles at length terminate in, and are continuous to the subjacent forepart of the Crura Medulla Oblongata.  
Those in the Thalami Nervorum Opticorum running obliquely down to part of the subjacent Crura and Caudex Medullaris.  
Those of the Nates and Testes running after the same manner, and terminating so too, only something lower.  
Those in the Annulary Process, which forasmuch as they have never before been taken notice of, I have caused to be engraved in a Figure by themselves, whose Medullary Tracts or Striae, furnished with Spirits both from the continuous medullary Caudex, and Productions of the Cerebellum too, of which the Annular Process is made, (by means whereof the Nerves appertaining thereto may be rationally supposed to be under the influence of both those Parts, conformable to what hath all-along been asserted;) are as visible, being more thick, and of a far harder consistence, than that of the Corpora Striata themselves, (tho' upon every attempt of cutting that Process, they may not appear so) and most of them terminating in a middle Medullary Tract, by means whereof there is the same inconveniency prevented, at least in some measure, as there is by that sepimentum of the Pia Mater, continued from the joining together of the Crura Medulla Oblongata, down quite through the Medulla Spinalis, (viz.) that at the same time the Nerves on one side may, (as Molinetti, 
Mol. p. 104  tho' in another place of the Brain, hath truly observed) by any morbid cause, be injured, those on the other may escape.  
Concerning these, seeing they seem to have a particular aspect or relation to those Nerves, whose originals we find nearest them, it may not be unreasonable to think they are particular Conduits, from whence the said Nerves are furnished with Animal Fluid, though at the same time we must allow a very free communication betwixt them all.  
And consequently, we may suppose the first of those to convey Spirits from the globous medullary part of the Brain next to it, by Vienssenius called the Superior. Part of the Centrum Ovale, down to the subjacent medullary part of the Brain, to augment those which are produced lower, and particularly for the service of the Olfactory and Visory Nerves, which last hath more eminently its Supply from the Thalami Nervorum Opticorum.  
The second sort, or the transverse Striae's of the Corpus Callosum, to convey an additional Supplement by way of the wreathed Tracts in the hinder Columns of the Fornix, to the Crura Medulla Oblongata, where they become continuous to the reflexed part of the Lateral Ventricles backwardly, for the service also of the aforesaid two Pair of Nerves, but more particularly to those arising lower either on the Annular Process or Caudex Medullaris.  
Those of the Thalami Nervorum Opticorum and Natiform Processes, the first of which lies upon, and is continuous to the subjacent medullary part of the Crura Medulla Oblongata, the other to the Caudex Medullaris, may be supposed to derive Spirits on the behalf of those Nerves which spring from any adjacent parts, whether on this or the other side of the Annular Process or Caudex Medullaris.  
And of this sort are the Optic Nerves, which are supplied immediately from the first of those Medullary Prominencies, and not unlikely from those fair Medullary Tracts aforementioned, running from the Root of the Fornix, extending themselves all the way between the Corpora Striata and Thalami Nervorum Opticorum, in which last at length they are obliterate. The Third, Fifth, Sixth, and First or hard Branch of the Auditory Nerves, mediately by continuity of them with the Annular Protuberance, to all which the other or lesser Medullary Prominencies called Nates, by virtue of their continuity with the subjacent parts, may be supposed to contribute something also: and these seems to be better provided for than the rest of the Nerves, inasmuch as besides this way of being supplied from the Cerebrum, they have also another very visible, and much larger, from the Second Process of the Cerebellum, of which the Annular Protuberance is made, and this seemingly not without a provident Design of Nature, seeing the Nerves which are derived thence are much larger, and have a greater Task of service laid upon them than any others of the whole Brain, as hath also the Par Vagum, or eighth Pair, which therefore, by virtue of its insertion between the Chordal or third Process of the Cerebellum and Corpus Olivare (and not according to Dr. Willis, from the points or extremities of the Corpora Pyramidalia) hath a double tribute of Spirits, one from the Caudex Medullaris or Cerebrum, the other from the Cerebellum.  
And to this End or great Service it looks as though this Process was furnished with such a Texture as it appears to have, of strong, large, medullary Striae's, capable of receiving and containing a Supply from both Fountains.  
Whence it may not be unseasonable to remark, That not without show of good Reason I have all-along asserted the Propriety of the Brain to those Nerves in part, allowed by Dr. Willis to be no further affected by any Impressions of the Brain, than as first conveyed from it into the Province of the Cerebellum, and consequently to depend immediately on this last for influence entirely in order to convey Animal Spirits to those parts wherein they are inserted.  
Upon the Caudex Medullaris, on its under side contiguous to the hinder Extremities of the Annular Process, are situate the Corpora Pyramidalia and Olivaria, over-against which are the two long Medullary Tracts lately taken notice of, seeming to come from the transverse Medullary Process behind the Testes, and terminating in those other transverse Medullary Processes before the entrance into the Fourth Ventricle on the other side, by which there may be conveyed a considerable Portion of the Animal Fluid to the Pathetic Nerve, which hath its rise from the first transverse Process, and to the soft or second Branch of the Auditory Nerve, which hath its rise from the second on that side, and also to the Ninth and Tenth Pair on the other side.  
And to conclude, From all these taken together, with the rest of the whole medullary part of the Brain, the Overplus of what is not spent upon the inmate Nerves of the Brain may truly be supposed to be promiscuously dispensed to all those other extraneous ones produced from the elongation of the Brain, called the Spinal Marrow. In which last there is this conformation or disposition of Parts differing from that of the Brain, that whereas in that the cineritious part is external, 'tis here internal; and this for very good reason, and by a provident contrivance of Nature, seeing that not only the cineritious part of the Brain serves for supplying those Nerves which have their original thence, as well as all the rest of the Spinal Marrow, and consequently aught to have the largest space and dimensions possible, which without this situation could not have been; but also without this contrivance the Nerves of this part must of necessity have had their originals from the cineritious part of the aforesaid Marrow, contrary to both the custom and convenience of Nature too.  

FIG. I. Exhibits the Basis of the Brain, with part of the Medulla Oblongata, the Blood-vessels being injected with Wax.  
A A The fore Lobes of the Brain.  
B B The hinder Lobes.  
CC The Cerebellum.  
D D The lateral Sinus'.  
E E The Vertebral Arteries as they pass between the first Vertebra and the Bone of the Occiput.  
F The Vertebral Sinus.  
G, &c The Dura Mater on the right side taken off from the Spinal Marrow, and remaining on the left.  
1, 2, 3 4, etc. The ten pair of Nerves belonging to the Brain, with seven of the Spinal Marrow.  
a The Foramen that opens into the Pituitary Gland from the Infundibulum.  
b b The two white Protuberances behind the Infundibulum.  
c c The two Trunks of the Carotid Artery cut off where they begin to run betwixt the fore and hinder Lobes of the Brain.  
d d The two Arteries joining the Carotids with the Cervical Artery, called the Communicant Branches.  
e e Two large Branches of the Cervical Artery, sometimes seeming as tho' they came from the Communicant Branch on each side, from the first of which the Plexus Chorocides hath its original in chief, and from the last the Plexus Chorocides of the 4th Ventricle.  
f Several little Branches arising from the Carotid Artery.  
g The Cervical Artery composed of the two Trunks of the Vertebral Artery within the Cranium.  
h h The two Trunks of the Vertebral Artery.  
i i i The Spinal Artery.  
k A small Branch of an Artery running through the 9th pair, broken off from its other part through inadvertency of the Graver.  
l l The Crura of the Medulla Oblongata.  
m m The Annular Protuberance, or Pons Varoliis.  
n That part of the Caudex Medullaris on the right side called by Willis and Vieussenius Corpora Pyramidalia.  
o That part on the same side called Corpus Olivare.  
p The foremost Branch of the Carotid Artery, dividing the fore Lobes of the Brain, consisting of two Branches, one of them only appearing here.  
q q Little Branches of Arteries helping to make the Plexus chorocides in the 4th Ventricle.  
r r r Branches of Arteries dispersed from the Cervical Artery upon and through the Annular Protuberance.  
s s Part of the 2d Process, or Podunculi, of the Cerebellum.  
** The Spinal Accessary Nerve.   

FIG. II. Showing the internal Basis of the Cranium, the Sinus' being injected with Wax.  
A A The Edges of the Skull.  
B B The Dura Mater upon the bottom of the Skull.  
C C The lateral Sinus'  
d d The superior, longer and narrower Sinus'.  
e e The inferior, shorter and wider Sinus'.  
f The Process of the Bone Cribriforme, called Crista Galli.  
g g Some small descending Branches of Veins upon the bottom of the Dura Mater.  
h h The first Branch of Arteries proper to the D. Mater.  
i i The second Branch of Arteries belonging to the Dura Mater.  
k The third Branch belonging to the Dura Mater.  
L The last hole of the Skull.  
m m Several Veins communicating with the inferior short Sinus'.  
n Part of the Os Jugale.  
o o The Os Ethmoeid, where the first pair of Nerves or mammillary Processes go forth.  
p p The Optic Nerves cut off.  
q q The Carotid Arteries cut off.  
r The third pair of Nerves vissible only on one side.  
S S The fourth pair of Nerves turned up.  
t t The fifth pair of Nerves on one side expanded before it is divided into its three Branches, on the other side whole; which Nerves, with its three Branches, are expressed in the third Figure.  
V It's foremost superior Branch on the left side, going out at the second hole of the Skull.  
w The sixth pair of Nerves.  
X The Intercostal Nerves, in this subject proceeding from two Branches of the fifth Nerve, joining with the body of the sixth Nerve.  
y Two Branches of the fifth pair of Nerves, in this subject running almost close to the 6th pair, being partly the Roots of the Intercostal Nerve, which creeps out of the Skull under and between the Coats of the Carotid Artery.  
z z The Body of the Carotid Artery, after it has entered the Cranium.  
1 1 The Glandula Pituitaria.  
2 2 The Circular Sinus.  
3 The Infundibulum.  
4 4 The Frontal Arteries.  
5 The place where the Lateral Sinus' begin to be declive and tortuous.  
6 The Dura Mater raised and reclined to show the subjacent Nerves.  
7 7 The seventh or Auditory Nerves.  
8 8 The eighth pair, or Par Vagum.  
9 9 The ninth pair.   

FIG. III. Being the Fifth Nerve, with its Branches, whilst within the Cranium.  
A It's Trunk.  
B It's Ganglion.  
C It's first or superior Branch, going out at the second hole of the Cranium.  
D Its second or middle Branch, going out at the second hole.  
E Its third or hindermost Branch, going out at the fifth hole.   

FIG. iv Shows the superior and lateral Sinus' of the Dura Mater, opened after they had been injected with Wax.  
A A The third or longitudinal Sinus.  
B B The first and second, or lateral Sinus'.  
C The fourth Sinus.  
d d d A Vein running on each side of the third Sinus.  
eeee Mouths of Veins opening into the longitudinal Sinus of the Dura Mater, after a contrary manner one to the other.  
f f The fifth Sinus at the bottom of the Falx.  
g The Torcular, where all the superior and lateral Sinus' meet.  
h h The tortuous part of the lateral Sinus running under the Cerebellum.  
i i The Veins entering the fourth Sinus from the Plexus Choroeides.  
k The place where the fourth Sinus arises.  
** The Specus or round hole at which the lateral Sinus' on each side go out into the internal Jugular Vein.  
l l Two large Veins, whereof one enters the fourth Sinus upon the second Process of the Dura Mater, so as to resist the course of the Blood in that Sinus, in its ascent to the Torcular; the other upon the same Process, so as to hinder its descent to the Internal Jugular, contrary to a conformation of Vessels which Vieussenius mentions in his third Table, H H.  
mmm Transverse Chordal Ligaments in the longitudinal and lateral Sinus'.  
n n Part of the Dura Mater on each side of the longitudinal Sinus.  
o o Portions of the Pia Mater.  
PP &c Divers small Veins on the Dura Mater, which enter those that run on the sides of the longitudinal Sinus, according to its length.  
qq &c The Veins of the Cerebrum as they appear under the Pia Mater, before they enter the longitudinal Sinus.  
R R The falcated Process, with its Veins which enter the fifth Sinus.  
S S The second Process of the Dura Mater.  
† † The beginnings of the Jugular Veins.   

FIG. V Representing the Brain in a middle section, the Blood-vessels being first injected with Wax.  
A A The Fornix cut off at its Roots and turned back.  
b b Its Roots at the beginning of the Thalami Nervorum Opticorum.  
cc, etc. The Thalami Nervorum Opticorum.  
d d That part of the Crura Fornicis which growing somewhat thicker as it turns off towards the Lateral Ventricles, runs over the Crura Medulla Oblongata, which being very prominent in Sheep, and Calves, helps to thrust it up into such a Protuberance as the Ancients called Bombyces or Hyppocampi.  
e e That part of the Plexus Choroeides which is made of the first Branch of the Cervical Artery, sometimes seeming as though it came from the Communicant Branch▪ in the Lateral Ventricles.  
f The place where those two Plexus' on each side meet under the Fornix.  
g g That other part of the Plexus which is made of the second Branch of the Cervical Artery joined with the first by a Communicant Branch not to be seen here, lying under the Crura Fornicis, which is expanded all over the Isthmus, becoming glandulous near to, and especially under the ●●a●d●la Pinealis covered here with the Fornix.  
h h Two large Veins coming from the top of the upper part of the Plexus down to the other Branch of the Plexus, all the length of the third Ventricle, and then terminates in the the fourth Sinus.  
i i The Trunks of several Arteries, appearing as they were cut off in dividing the Medullary † and Cineritious * part of the Brain.  
k k A Venous Branch of each side entering the Plexus Choroeides, from whence there are many slips branched upon the Corpora Striata.  
Δ Δ The Corpora Striata whole.  
l The Rima of the third Ventricle.  
m m A long Medullary Tract between the Thalami Nervorum Opticorum and Corpora Striata.  
nn, etc. The Centrum Ovale of Vieussenius.  
O The fourth Sinus of the Dur. Mater.  
P The Torcular, where the four, and sometimes five, Sinus' meet.  
Q Q The Lateral Sinus'.  
R A large Vein entering the Lat. Sinus' on one side.  
SS, etc. The Cerebellum covered with the second Process of the Dura Mater on its uppermost part,  
T T The Vertebral Arteries.  
V V the Vertebral Sinus'.  
W The Medulla Spinalis, with its integuments.  
x x The Style supporting the large Veins of the Plexus Choroeides in the third Ventricle.  
q q The Lymphducts of the Plexus Choroeides.  
Y Y Two of the Cervical Nerves springing from the Medulla Oblongata.  
† †, etc. The Medullary part of the Brain.  
**, etc. The Cineritious part.   

FIG. VI Being a draught of the Annular Protuberance, Med. Spinalis, etc. cut through the middle lengthway.  
A A The Crura Medulla Oblongata.  
B B The Annular Process, or Pons Varoliis divided.  
c c The Transverse Striae.  
e e The intervening Medullary Tract in which the Striae terminates on each side.  
f f The third or chordal Process of Dr. Willis.  
h The Spinal Marrow.  
i i Some part of the Cerebellum.  
k k The second Processes of the Cerebellum, which compose the Annular Protuberance.  
l l The cineritious part of the Medulla Oblongata.   

FIG. VII. Being the Cerebellum cut through on its hinder part, and reclined laterally.  
A A The Cerebellum.  
B B The arboreous ramification of the Meditallium of the Cerebellum appearing, being cut right downwards.  
C C The Pathetic Nerves.  
c c The Nates.  
d d The Testes.  
e The transverse Process whence the Pathetic Pair have their original.  
f The Glandula Pinealis.  
g g The first Process of the Cerebellum, running from it to the Nates here extended laterally.  
h h The third or Chordal Processes.  
i i The transverse medullary Process in the 4 Vent. from whence the soft Branch of the 7 N. has it original.  
k k The Medullary Process descending from the Transverse Process behind the Testes, down to the aforementioned other Medullary Transverse Process.  
l l The Originals of that Process a little too low.  
m m The eighth pair of Nerves.  
n The Calamus Script▪ or Extremity of the 4th Ventricle  
o The Spinal Marrow.  
P P The Accessary Nerves.  
q q The tenth pair of Nerves.     

THE TABLE.  

A  
ARtery Carotid, and the manner of its entrance into and distribution through the Brain. Page 32, 33.  
Where it parts with its borrowed Coat. p. 33  
Artery Vertebral, and its manner of entrance and distribution. p. 35  
Artery Cervical ibid.  
Why not Conical p. 38  
The Communicant Branches of Arteries. p. 36  
Their Use and Benefit ibid. & 37  
A small Branch of Arteries not before observed p. 38  
Why the Arteries of the Brain enter not the Cranium with the Veins p. 27  
Artery Spinal, how the Blood is forced into it, p. 37  
Animal Spirits, how more plentifully produced, p. 54  
Anatomy Comparative, its use p. 54  
Arteries, why their Ramifications are over-proportionable to the Trunks in the Brain, p. 55  
The Use of the narrowness of the Communicant branches, p. 56  
How the Carotid Artery in Brutes comes to be smaller above the Dura Mater than under it, p. 65  
Animal Fluid, what, p. 91, 108, & 155  
How it passes out of the Carnous Fibres, p. 109  
Its effect in glandulous and other parts not serviceable to Muscular Motion, ibid.  
It's production, p. 115  
Anus, p. 124  
Aquae emissarium of Vieussenius, p. 132   

B  
Brain, its Vessels in general, p. 20  
Their kinds, ibid.  
Blood vessels, their different distribution in relation to the Brain itself, and its Integuments, ibid. & 26  
The reason of this different distribution, p. 27  
Blood-vessels belonging to the Brain itself only, p. 32  
What proportion the Blood-vessels of the Brain bear to the rest of those of the whole Body, p. 32, & 38  
The remarkable propagations of its Arteries, p. 35  
Blood-vessels belonging to the Nerves, p. 33, 34  
Blood in the Sinus' hath two contrary torrents, p. 53  
The effects thereof, ibid.  
How the circulation of the Blood comes to be retarded in the Brain, p. 53  
The Bony cell where the Sinus' go out into the internal Jugular, p. 53  
The effect of its structure, ibid. & 54  
The Brain, how distinguished, p. 87, 113  
It's two Substances, ibid.  
Their structure, p. 89, 90  
Why of a different colour, p. 90, & 92  
Blood, why red p. 91  
How the Brain is suspended, p. 7, 8.  
Its Lobes and particular description, p. 113, 114  
It's hinder Lobes stretched backwardly beyond the Cerebellum, ibid.  
Original of its medullary part, p. 115  
Bombyces, vide Hippocampi, Blood-vessels of the Nerves, p. 144  
Watery Bladders instead of Brain, p. 178, 179  
Brain petrified, p. 179  
Propriety of the Brain to Nerves often thought under the power of the Cerebellum, p. 198   

C  
Consent of Parts. p. 19  
Carotid Artery, vid. Artery.  
The Circular Sinus, p. 43  
Communicant Branches between the Carotid and Cervical Arteries, their Use, p. 55, 56.  
The Cortical or cineritious part of the Brain, p. 88  
It's medullary part, ibid.  
Corpus Callosum, p. 115  
It's Striae, p. 116  
Centrum Ovale of Vieussenius, p. 117  
Crura Fornicis, p. 818  
Commissura Crassioris Nervi Aemula of Willis and Vieussenius, p. 126  
Corpus Callosum, p. 115  
Centrum Ovale, p. 117  
Crura Fornicis, p. 118  
Corpora Striata, p. 120  
The Cerebellum, p. 133  
Its d●fference from the Brain, p. 135  
Corpora duo alba pone Infundibulum, p. 140  
Olivaria, ibid.  
Power of the Cerebellum, p. 170, 173   

D  
The Dura Mater, p. 1  
Its manner of adhesion to the Cranium, p. 2  
Is double, ibid.  
What sort of Fibres, and their distribution, p. 3  
Their Use, p. 4, 5, 6  
How affected in some Distempers, particularly in Vapours, p. 6  
Its Nerves, ibid.  
Its Processes, p. 7, 9  
Their uses, p. 7, 8, 9  
Its Blood vessels apart from the Brain, their number and distribution, p. 20, 22  
Two sorts of Dropsies of the Brain observed by Tulpius and Wepter, p. 59  
Their Solution, ibid. & 60   

E  
Elasticity of the Blood, p. 53  
The Effects of that being weakened, ibid.  
Extravasation of the Nutritious Fluids, its effect, p. 97  
Elasticity not competent to the first principles of Bodies, p. 100  
The Occasion of it in other Bodies, ibid.  
Elasticity it's aequilibrium in the whole compapages of Muscles, p. 105  
The Effect thereof. ibid. & 106  
Experiments by Injection, of what use in Muscular Motion, p. 110   

F  
The Falx and its particular uses, p. 7, 8, 9  
Is wanting in several Creatures, and why, p. 9  
Fibres of the Dura Mater do the office of Valves, p. 5  
Fleshy part of the Body, what, p. 94  
Fluids of the Body, their different motions, p. 96  
Fornix, p. 117  
It's Crura, p. 118  
The Fornix of Vieussenius, p. 115  
The Fornix commonly so called, p. 117  
It's Fimbria, according to Vieussenius, p. 118  
It's Crura, ibid.  
How natural and vital Functions relate to the Cerebellum, and with what difference, p. 170, 171  
How they come to be not under the power of the rational Soul, p. 174  
How performed when the Brain is utterly incapable of acting, p. 177   

G  
The Glandula Pituitaria enclosed in strong Membranes p. 46  
No Serum can get through its Integument, ibid. & 75  
Glands of the Plexus Choroeides, p. 63, 63  
The Glandula Pituitaria not capable of carrying an Excrementitious humour, p. 69, 73  
The Gland. Pit. its situation, p. 71  
Is not suspended in Men as in Brutes, ibid. & 73  
In substance it differs from all other Glands, ib.  
Is of two sorts, and why, p. 81  
In what manner the Lympha gets into it, ibid.  
The Glandula Pinealis, its situation and connexion, p. 83  
Is of the Conglobate kind, p. 84  
Errors of Des Chartes, Lower and others about it, p. 84, 85  
Geminum Centrum Semicirculare of Vieussenius, p. 122   

H  
Headache, how happening in Fevers, p. 29  
From the closeness of the Pores in the Cranium, p. 42  
Two sorts of Hydrocephalus, p. 59  
Hippocampi Arantii, p. 118  
Their Striae, ibid.   

I  
Injection with Mercury makes Blood-vessels appear, p. 34  
The Infundibulum, p. 77  
The difference between it in Men and Brutes, ibid.,  
It's two Ducts in Brutes, p. 78  
Its Office, p. 79, 80  
Infundibulum, the passage into it by three Foramina's, p. 124  
Isthmus, p. 125  
Instinct, what, p. 162, 163  
The differing effects of some Impressions upon the Soul, p. 181, 182, 183  
Transmission of Impressions, according to Doctor Willis, improbable, p. 184, 185  
Difference between involuntary and inadvertent acts, p. 187  
Internal Senses, their seats, p. 190   

L  
Lsgaments of the Sinus', p 51 Their uses p, 52, 56  
Lateral Sinus', p. 40  
Longitudinal Sinus', p. 41  
Lymphducts of the Brain, p. 61, 62  
Lympha, how generated within the Ventricles, p. 81, 82  
To what end, ibid.  
Laughter, how made, p. 181  
Why peculiar to Man, p. 182  
Libidinous Actions, how caused, p. 181, 182   

M  
Membranes of the Brain, vid. Dura and Pia Mater.  
Muscular Motion, p. 99  
Divers Opinions about it, ibid.  
Muscle, its inflation or contraction, p. 102, 106  
Muscle, how contracted or swelled by force, p. 104  
Muscles, the effect of their being cut through, p. 105  
Muscles, their hardness and swelling in contraction, whence caused, p. 106, 107  
Muscular Motion, some particular Phoenomena about it solved, p. 110, 111  
Muscular Motion made by the Nervous Fluid alone without concurrence of the blood, p. 177  
A Medullary Tract not before observed, p. 123  
Medulla Oblongata, p. 139  
It's Crura, ibid.  
Animal Motion, p. 158  
Motion voluntary and involuntary, p. 159, 160  
Two sorts of Motions in Brutes, p. 161  
Medullary Tracts of the Brain, p. 192   

N  
Noise in the Head, how occasioned, p. 29  
Nervous Juice, p. 88, 93  
Nutrition p. 88, 89, 94  
Nervous Juice, how generated ibid.  
Nerve; its structure p. 93  
The effect of its being taper ibid. & 102  
Nates p. 125  
Nerves Olfactory, p. 143  
— Optic p. 144  
Motorium or third Pair p. 145  
Patheticum or fourth pair p. 146  
The fifth pair p. 147  
The sixth pair p. 148  
The Intercostal ibid.  
The seventh or auditory pair p. 149  
The eighth or Par Vagum  
The Accessary Spinal Nerve p. 151  
The ninth pair p. 142  
The tenth pair p. 153  
The structure of the Nerves p. 154  
Nerves their different functions p. 157  
The effects of Communications betwixt Nerves, p. 175, 181  
The Nerves within the Cranium, how supplied with Spirits from various medullary Tracts of the brain, p. 194, 195, etc.   

O  
Optic Nerve its original p. 123  
External Objects, how they act p. 158  
Improportionable actings of the Object p. 186  
Organization of the brain p. 189  
Overplus of the Animal Fluid of Cerebrum with its use p. 199   

P  
The Pia Mater, p. 10  
Why called Choroeides ibid.  
It's particular distribution ibid.  
How to isnd it in the Ventricles p. 11  
Is double every where, but where most visibly, p. 12  
It's inward Lamina is of a Netlike Texture. p. 15  
Its uses p. 16  
Its Blood-vessels, which are of two sorts, p. 18, 19  
How it invests the Nerves and their distinct Fibrils p. 19  
How the Arteries belonging to the Brain itself are ramified through it p. 33  
How some branches of the Carotid and Vertebral Arteries are exempt from it, p. 34  
The Processes of the Dura Mater, with their distribution and use p. 7, 8, 9  
Pulsation of the Sinus', whence p. 50  
The Plexus Choroeides of the Brain p. 57  
It is double ibid.  
Hath two different Originals ibid.  
What they are ibid.  
Where the first part gins to be glandulous, p. 58  
Where the first part of the Plexus terminate and meet p. 58  
Where the second part gins to be retiform, ibid.  
The double connexion of the two parts of the Plexus ibid.  
Two Veins joining the first part of the Plexus in its extremity p. 61  
It's large reductory Veins entering the fourth Sinus ibid.  
Its Lymphducts ibid.  
It's Glands p. 62  
Their Use ibid. & 63  
Its situation and use ibid.  
The Pituitary Gland hath Veins p. 66  
Processus Lentiformes, vid. Corpora Striata.  
Passage into the Infundibulum p. 123  
Processus Annularis, or second Process of the Cerebellum p. 129, 135, 140  
Its Striae p. 136  
Processus Natibus antepositus p. 125  
Processus Nervi Aemulus p. 126  
Processus Nervuli Aemulus p. 128  
The Plexus Choroeides of the Cerebell. p. 134  
Processus Vermiculares p. 135  
The first Process of the Cerebellum ibid.  
The third or Choadal Process of the Cerebellum p. 136  
The medullary transverse Processes of the fourth Ventricle p. 136  
The medullary Processes descending to those transverse ones p. 137  
The Plexus Choroeides of the Cerebellum, p. 133  
Perception or Passion, what, p. 158   

R  
The Receptacula Sellae Aequinae, etc. of Vieussenius not existent in Men p. 45  
Their Use impossible p. 46  
The Rete Mirabile p. 64  
Always existent in Men ibid.  
It's situation ibid.  
Why smaller in them than Brutus' ib. & 65  
The effect of its being so large in Brutes, p. 65  
Is differently situated in Men and Brutes, p. 72  
Hindermost Roots of the Medulla Spinalis, what formerly p. 126  
Respiration, how performed p. 165  
Why a Child unborn respires not, p. 168  
Why Respiration ceases upon cutting the Cerebellum, p. 174   

S  
Sinus' of the Brain p. 39  
Their number ibid.  
The Lateral ones p. 40  
The third or longitudinal p. 41  
The fourth or internal one ibid.  
Four other smaller Sinus', and their first Author, p. 42, 43  
The Circular Sinus p. 43  
It's particular description ibid. & 44  
Its use p. 47, 48  
No Serum can be separated but by proper secretory Ducts p. 47  
The Sinus' have no pulsation of themselves, p. 50  
Their pulsation is from the Brain, ibid.  
The different Ligaments of the Sinus' p. 57  
The use thereof ibid.  
The blind Cavities or Diverticulums of the Sinus' p. 52  
Their uses ibid.  
The structure of the Sinus' p. 53  
Effects thereof ibid.  
Animal Spirits, how made more plentifully, p. 54  
Why the Sinus' grow so wide on a sudden, ibid.,  
Their difference of structure p. 56  
The longest Sinus commonly burst in strangled bodies ibid.  
How the blood passes the Lateral Sinus' in different positions of the Brain p. 54  
Structure of the Brain Vascular, p. 91  
Secretion, how made, p. 91, 92  
Sensation, how explained p. 88, 101  
How made, p. 158  
Corpora Striata p. 115, 120  
Septum Lucidum p. 119  
It's Striae ibid.  
The Spinalis Medulla in a Tortoise officiating instead of the Brain p. 176  
Sneezing, why peculiar to Man p. 182  
Commune Sensorium, what, p. 191  
Striae of the Annular Process, why large, p. 193, 197  
Why terminating in a middle medullary Tract, p. 193  
Conformation of the Spinal Marrow differing from that of the Brain, and why p. 200   

T  
Torcular Herophili p. 42  
Tractus Medullaris Th. Nerv. Opt. interjectus of Vieussenius p. 84  
Tract. Med. Natibus antepositus of Vieussen. ibid.  
Transpiration, what, p. 95  
Conspiration of Hypocrates ibid.  
Tone of Parts p. 109  
Testes p. 125  
Thalami Nervorum Opticorum p. 121  
Tria Foramina relating to the Insundibulum, vide Insundibulum.   

V  
Vapours, commonly so called, how sometimes affecting the Fibres of the Dura Mater, p. 6  
Some Veins of the D. Mater entering the third Sinus p. 41  
Vertebral Artery, vide Artery.  
Veins of the Dura Mater enter the Brain with the Arteries contrary to those of the Brain itself p. 26, 27, 28.  
Two Veins entering the Circular Sinus, p. 45, 46  
How the Veins enter the Sinus' p. 52, 53  
The effects of their different entrance, p. 54  
The Veins have a different disposition in the Sinus' of Brutes, from what they have in Men p. 54  
Veins of the Corpora Striata p. 61  
The large reductory Veins of the Plexus Choroeides, ibid.  
Vapours condensed into Lympha p. 81  
Vascular constitution of Parts p. 91  
Veins, how continuous to Arteries ibid.  
Vessels containing the Animal Fluid are capillary productions of Arteries p. 93  
Veins only productions of Arteries p. 94  
Vessels their minuteness p. 95, 96  
Vessels of Vessels ibid.  
Ventricles of the Brain p. 117  
Valvula major p. 128, 119  
its situation and use p. 128, 129, 130, 132  
The three Ventricles of the Brain p. 117  
Vulva Cerebri p. 124   
FINIS.   

ERRATA.  
PAGE 9 l. 14. for to read towards; p. 16: l. ult. for from which r. which from; p. 32. in the title of the Chapter, for Veins r. Vessels; p. 32. l. 13. after Veins insert which last have already been treated of; p. 64. l. 5. deal only; p. 89. l. 16. Vitrious r. Vitrous; p. 92, l. 29. for Septometry r. Leptometry; p. 102. l. 3. for contracted r. contracts; Ibid. l. 29. for reflexed r. relaxed; p. 109. l. 18. for hastening r. happening; p. 117. l. 28. for Semicirculari r. Semicirculare; p. 119. l. 12. for becomes r. become; p. 138. from And therefore in the 7th line to the end of that Paragraph, leave it out: p. 137. l. 7. for above r. below; p. 168. l. 8. after passage add at least but very little.  
 
 
M. Ʋander Gucht Sculp: