A Letter of Dr Wallis to Dr Tyson, concerning Mens Feeding on Flesh

II. A Letter of Dr Wallis to Dr Tylon, concerning Mens feeding on Flesh. Oxford, Feb. 3. 1684 SIR, Though I have not had the opportunity of Acquaintance with you, I desire you will give me leave to suggest to you a Question or two in your Profession, relating to Comparative Anatomy. You may perhaps censure me, as an Interloper in your Faculty: But while I was (at Cambridge) but a young Student in Philosophy, I look'd upon the Medicinae pars Physica, as a piece of Natural Philosophy; and did accordingly apply myself to it, (though without any design of practising the Pharmacentick,) and to Anatomy in particular. And Dr Glisson (who was then our Publick Professor of Physick, and under whom I kept, as they call it, a Physick Aë) hath since told me, that I was the First of all his Sons, that did (in a publick Disputation) maintain Dr Harvey's Circulation of the Blood, in the year 1641, (when it was but a New Doctrine,) being then able to trace it through the Arteries and Veins of the whole Body, better than now I can, (having since forgotten much of the particularities thereof, upon my diverting to other Studies.) Which I hope you will admit as an Excuse for my Interloping. Now, I remember to have read (about fifty years ago) in one of Gassendus's Printed Epistles, (printed among some previous pieces of his, before the body of his Works was published,) a suggestion of his, which he seems to espouse as his own opinion, ) as if he thought it not (originally) Natural for Man to feed on Flesh; though by long usage (at least ever since the Flood) we have been accustomed to it, and it is now familiar to us; but rather, on Plants, Roots, Fruits, Grain, &c. And I take it to be the Opinion of many Divines, that before the Flood, Men did not use to feed on Flesh, because of what we have in Gen. 9. 3. where God says to Noah, (after the Flood,) Every moving thing that liveth, shall be meat for you, even as the green Herb have I given you all things: Compared with Gen. 1. 29. where God says to Adam, I have given you every Herb bearing Seed, and every Tree in the which is the fruit of a Tree yielding seed, to you it shall be for Meat; but without any intimation of his feeding on the Flesh of Animals, which seems to be an insinuation to that purpose, and is commonly taken so to be. Yet, I confess, I have some doubt therein remaining, seeing that we find, very early, that Abel was a Keeper of Sheep, as well as Cain a Tiller of the Ground, both Employments seeming equally in order to their Food and Sustenance. And their first Cloathings, were the Skins of Animals. It may perhaps be thought, that these Animals were Slain for Sacrifice, and the Sheep fed only for that purpose, but even their Sacrifices seem to have been offered but as a Portion (or First-fruits) of things appointed for Food; and that as Cain was not to Sacrifice the whole fruit of his Tillage, so neither was Abel, the whole product of his Sheep, but the best thereof (the Firstlings of his Flocks, and the fat thereof) and reserving the rest for his own use. And it cannot seem likely, that God would give to Noah after the flood, a greater Dominion over other Animals, than had been given to Adam, in Paradise before the fall. And I should then consider this permission to Noah, not as contra-distinct from that to Adam, (as of what is now permitted, which before were not;) but rather as Introductive of the Prohibition which presently follows, to wit, Though he might eat Flesh, even as the green Herb, (so far as it might be wholesome food:) yet, not with the Blood thereof; that is, not Raw flesh; not carnum crudum, or carnum cum cruroe. I add also, that the same Rule is given to other Animals, Gen. i. 30. as is to man, at ver. 29. I have given them every green herb for meat: Yet there are, we know, many Carnivorous Animals, without any further Permission that we know of. But (without disputing it as a point in Divinity, Whether men, before the Flood, did or might feed on Flesh, supposing it to be wholesome nourishment;) I shall consider it (with Gassendus) as a Question in Natural Philosophy, whether it be proper Food for Man. The consideration insisted upon by Gassendus, is from the structure of the Teeth, (and, as I remember this only,) that our Teeth are mostly either Incisores, or Molitores; not such as (in Carnivorous Animals) are proper to tear Flesh, except only 4, which are called Canini: As if Nature had rather furnished our Teeth, for Cutting Herbs, Roots, &c. and for bruising Grain, Nuts, and other hard Fruits, than for Tearing Flesh, as Carnivorous Animals do, with their Claws, and sharp Teeth. And, even when we feed on Flesh, it is not without a preparative Coction, by boiling, roasting, baking, &c. And, even so, we forbid it to persons in a Fever, or other like distempers, as of too hard digestion. And Children (before their Palats are vitiated by custom) are more fond of Fruits than of Flesh-meat. And their breeding Worms is wont to be imputed to their too early feeding on Flesh. This ingenious Conjecture of Gassendus, did presently suggest to me another speculation, which seems not less considerable. There is in Swine, Sheep, Oxen, and, I think, in most Quadrupeds that feed on Herbs or Plants, a long Colon, with a Cæcum at the upper end of it, or somewhat equivalent, which conveys the Food, by a long and large progress, from the Stomach downwards, in order to a slower passage, and longer stay in the Intestines: But in Dogs, of several kinds, and I suppose, in Foxes, Wolves, and divers other Animals which are Carnivorous, such Colon is wanting; and, instead thereof, a more short and slender gut, and quicker passage through the Intestines. That which I would propose hereupon is, that you would please to consider, as your leisure and opportunity permit, whether it do generally hold, or how far forth, that Animals which are not Carnivorous, have such Colon, or somewhat equivalent; and, that those which are Carnivorous have it not. For if so, it seems to be a great Indication, that Nature, which may be reasonably presum'd to adapt the Intestines to the different sorts of aliments that are to pass through them, doth accordingly inform us, to what Animals Flesh is proper aliment, and to what it is not; and that from thence we may judge more solidly, than from the structure of the Teeth only, whether or no Flesh were designed as proper food for Man. Now it is well known, that in Man, and, I presume, in the Ape, Monkey, Baboon, &c. such Colon is very remarkable; and the like in your ingenious and accurate dissection of your Homo Sylvestris, which may therefore be thence conjectured, not to belong naturally to the Carnivorous Tribes, if that rule hold. 'Tis true, that the Cæcum in Man is very small, and seems to be of little or no use: But in a Fetus, it is in proportion much larger than in persons adult. And it's possible, that our Customary change of Dyet, as we grow up, from what originally would be more natural, may occasion its shrinking into this contracted posture. But I add this also, that Man's being indu'd with Reason, doth supply the want of many things, which, to other Animals may be needful. Man is not covered with such quantity of Hair or Feathers all over his Body, which to other Animals serve for Cloaths; but can, by his use of Reason, supply himself with Cloaths suitable to every Climate, and different Seasons. He is not furnished with Claws, Hoofs, Horns, &c. which serve for Arms to other Animals, but can, by the use of his Reason, supply himself himself with Weapons, and other Instruments for different occasions, to much better advantage. And, in the present case, though raw Flesh be not proper, as 'tis to some other Animals, he can by Preparative Coctions, and other Expedients, render it more agreeable. Nor is he wholly destitute of Dentes Canini; but is indeed furnished with all sorts of Teeth, for all sorts of wholesome Food. I take the Sheep, the Goat, the Swine, the Ox, the Horse, the Ass, the Camel, the Elephant, the Hart, the Hare, the Rabbet, the Mouse, &c. not to be carnivorous; but the Dog, the Wolf, the Fox, the Cat, the Lion, the Leopard, the Tiger, &c. to be naturally carnivorous, which of all these have, or have not the Colon, or what other distinctive mark may be observed between these different Tribes of Animals, I think may deserve a serious consideration. I submit the whole to your Enquiry, who have more opportunity, by your Experience and Conversation, to judge of it, than I can pretend to have. There is another Point, which (if I have not already trespassed too far) I had thoughts of proposing to you about the structure of the Ear. But I shall omit that at present (that I be not at once too tedious) and beg your pardon for having trespassed so far. Resting Yours to serve you, John Wallis. The Answer of Dr Tyson to the foregoing Letter of Dr Wallis, concerning Man's feeding on Flesh. London, Jan. 16. 1703. SIR, Before I return you my Answer to your obliging Letter, I must beg Pardon that I have deferred it so long: And do assure you, it was not for want of a just Respect and Esteem (which all the Learned World deservedly have had for so long a time of your great worth) that occasioned this Delay: But other affairs, which it were needless to trouble you with. I do now give you my hearty Thanks for the honour you have done me therein: And our whole Faculty is no less obliged to you, for your so early defending so momentous a Doctrine, as that of the Circulation of the Blood, which, for some time afterwards was so warmly opposed, both by our own Countrymen and Foreigners. I doubt not, had you continued these Studies, the force of so great a Genius would have made as great discoveries, as that you then defended; and since have done in the Mathematicks, whereby you would have demonstrated many important truths in our Faculty, which now are received only as meer conjectures. The Argument you propose, from the Conformation of the Intestines, why Man should not be Carnivorous, seems far more Rational than that which Gassendus urges, from the structure of the Teeth. Though it must be owned, there is nothing he hath omitted, that could have been said on that subject, to favour it. I shall beg leave to give you my thoughts freely on this occasion; And, if in my Answer some things may seem not exactly adapted to the question in hand; if otherwise they may not be unuseful, I hope they will not be unacceptable to you. But, before I come more particularly to consider your Hypothesis, give me leave to remark, That, had Man been design'd by Nature not to have been a Carnivorous Animal, no doubt there would have been observed, in some part of the World, Men which did not at all feed upon Flesh. But since no History (as I know of) furnishes us with such an instance, I cannot but think what hath been done universally by the whole Species, must be Natural to them. What the Pythagoreans did, in Abstaining from Flesh, was upon the notion of a μεταμόρφωσις, or Transmigration of Souls, a mistake in their Philosophy, and not a Law of Nature. And, though in some Countries Men feed more freely on Flesh, in others more sparingly, this is owing to their own choice, from the Advantage they find thereby. Nature having given Mankind Reason, he can, or ought to elect what food he finds most agreeable to him, in the Climate he lives in; and is not determined to any one sort, but has liberty to all. And 'tis as probable, that the Antediluvian World had so likewise. Wherefore I shall wholly acquiesce in your determination of this point, and am fully satisfied with the Reasons you give for it. We shall therefore now, as you direct, consider it as a Question in Natural Philosophy; Whether from the Observation of the structure of the Parts in Man, we can find reason to think Nature did, or did not, assign him to be Carnivorous. For I am of Gassendus his opinion, Licet ex conformatione Partium Corporis Humani, conjecturas desumere ad Functiones mere Naturales. For, all the Knowledge we have of the Uses of the Parts in Animal Bodies, is by observing Nature's wonderful contrivance in the formation of them; who most wisely adapts adapts them to the Uses they are designed for. Not because they are casually so and so formed, are they necessarily put to such and such uses: But therefore they are so contrived, that they may perform such Offices in the Economy of Animal Bodies, as Nature intended them for. Longe proinde facessat illa Empedoclis, Epicuri, aliorumque Opinion, sc. Membra Animalium non esse facta propter Usum; sed, Membris ita caeo factis, & coalescentibus, ipsorum uuum Accomodatione Experientia, varia ad-inventum, saith the same Gassendus. And there are several remarkable Instances I have given in my late Treatise of the Homo Sylvestris, that sufficiently confutes such Unphilosophical Atheists. I come therefore now more closely to our Business. Since you have so fairly represented Gassendus his Opinion and Argument from the structure of the Teeth, why Man should not be designed by Nature to be Carnivorous; and have likewise sufficiently, I think, answered his Reasons; I shall wholly pass that over at present: And shall only consider the Observation you have made of the different Formation of the Intestines in Carnivorous Animals, from those that are to be met with in such as do not feed upon Flesh, but other food. And indeed this seems to me to be of far greater weight, and to carry more strength in it, than any thing I have met with before. And all the Instances you give are very True. We shall therefore first of all observe, That the Ductus Alimentalis (for so I call the Gula, the Stomach, and Intestines; all which make but one continued Canalis or Ductus;) This Ductus, I say, is properly the true Characteristic of an Animal, or Proprium quarto modo. For there is no Animal but hath such a Ductus; and whatsoever hath such a Ductus, may properly enough be ranged under the Clasps of Animals. Plants receive their Nourishment by numerous Fibres of their Roots, but have have no Common Receptacle for the Digesting the Food received, or Vent for carrying off the Recrements: But in all, even the lowest degree of Animal Life, we may observe a Stomach and Intestines; even where we cannot perceive the least Formation of any Organ of the Senses, unless that common one of Tactus; as in an Oyster. Where also we may observe a sensible Muscular Motion, or Contraction; though it would be difficult to assign what Part should be reckoned the Brain, or Medulla Spinalis, from whence the Nerves arise that give it so strong a motion. Now this Ductus being so Principal a Part in an Animal, and its Use being for the Receiving and Digesting the Food, and Distributing the Chyle; 'tis reasonable to suppose, that, according to the difference of the Food, the structure of the Organ should be also Different; or, where the Organ was the same, there the Use was the same too, for the Receiving, Digesting and Distributing the same sort of Food. Man therefore having these Parts formed, not like Carnivorous Animals, as you well observe; but more resembling those that live on Herbs, Roots, Fruits, &c. it may seem reasonable to conclude, that Nature never designed him to live on Flesh; But, that the Wantonness of his Appetite, and a depraved custome, had inured him to it. For, as Gassendus remarks in the same Epistle I have so often quoted, (viz. Epift. Jo. Bapt. Haimont. operum Tom. 6. pag. 19.) Custome may make that seem Natural to us, which Nature never intended. As he instances in a Lamb that was bred on Ship-board, which refused the green Pasture of the Fields, for the Diet it was formerly used to. And I have often seen here in London (and it being a thing so unusual, I take leave to mention it) a Horse, that, with a great deal of pleasure, would eat Oysters, scranching them, shell and all, between his Teeth, and swallowing them; And this he took to by accident, being left at a Tavern door, where stood a Tub of Oysters: And since hath frequently done it, whenever they were offered him. Now Gaffendus observes, that Children (from whom he thinks we may better take the Instincts of Nature, than from our Appetites when depraved by Custome) are much fonder of Fruit than of any Flesh that is offered them; and therefore he supposes it more Natural to them. The Instance you give, wherein the structure of the Intestines of Carnivorous Animals is different from that in Men, is, that the former want a Colon; whereas in Men there is a very large one, which is not to be observed but in such Animals as live upon Fruits, Roots, Herbs, &c. What therefore you propose to me, is to consider, Whether it does generally hold (or how far forth) that Animals that are not Carnivorous have such a Colon, (or somewhat equivalent) and those that are Carnivorous have it not. I shall begin with those Animals that are Carnivorous, and have no Colon, or large Caecum. For though they may have the Appendicula Vermiformis (as some Anatomists call it) yet if that is not extended or filled with the faeces, which the other Guts contain, I think it not properly to be esteemed as a distinct Gut, or to come into that number, since here it does not perform the office of a Gut, in containing the Food or Excrement. So, in a Man, in Dogs, and other Animals, when it is thus contracted, I exclude it out of the number of the Intestines, though by use and custome (but I see no reason for it) 'tis commonly reckoned one of the Intestina crassa. Animals therefore that have no Colon, or large Caecum, though some of them have this Appendicula Vermiformis, and are Carnivorous, I reckon. 1. The Dog-kind; under which, beside their own species, may be included the Fox, the Wolf, the Coati Mondi, the Badger, the Otter, &c. 2. The Vermin-kind; as the Weasel, the Fitchet, the Polecat, the Martin, &c. Both these kinds have a Bone in the Penis; have no Colon or Caecum; some have the Appendicula Vermiformis; and all are Carnivorous. 3. The Cat-kind; to which may be reduced, besides their own Species, the Lyon, the Tyger, the Leopard, the Lynx, the Catamountain, &c. Tis true, the French Memoirs for the History of Animals, tells us, that a Lyon has a Colon 18 inches long, and an Appendicula Vermiformis 3 inches; and that in a Lioness the Colon was two foot, and the Caecum two inches long. Now I question whether we may properly call this a Colon or no: For tho the Gut about this place may be more extended than in others, yet not having those Ligaments whereby the Gut is corrugated into Cells, as in a Humane Body, I think strictly it does not deserve that name. So in a Cat, the Intestine, at the place of the Colon, is larger, but, for the same reason, shall not call it a Colon. And though a Cat has a small Projection of the Gut, which may be called a Caecum, because it contains faeces; yet, since 'tis so very short, we will not insist on it. 4. A Boar hath no Colon or Caecum. 5. A Mole, which feeds on Worms and Insects, has no Colon or Caecum. In the next place we will consider those Animals that are not Carnivorous, but live upon Herbs, Fruits, Roots, &c. all which have a Colon, or Caecum, or both; For, as to your Query, I think it much the same, whether they have either one of these only, or both; provided that the Capacity of the Gut there, be large and extended, and do contain faeces. I will ennumerate first those Animals that have both a Colon and a Caecum, or at least a Colon. As 1. The Horse-kind; in which may be included the Ass, the Mule, &c. which have a large Colon and Caecum. 2. The Elephant hath a great Colon and Caecum. 3. The Dromedary and Camel, a long Colon. 4. The Swine-kind, whose Species is numerous, have a large Caecum and Colon. 5. The Guiny-pig, a Colon and Caecum. 6. The Castor, or Beaver, has a large cellulated Colon and Caecum. 7. The Hare-kind, has a large Colon and Caecum. The Caecum in the Rabbit is very long, and in the middle, a cochlear valve. 8. The Ape and Monkey-kind, have a cellulated Colon, and short Caecum. Now there are several Animals that have a large Caecum and no Colon, and these too are not carnivorous, but live upon Grass, Fruits, Roots, &c. as 1. The Neat-kind, as the Ox, the Barbary Cow, &c. 2. The Sheep-kind, which is numerous. 3. The Stag-kind, to which may be referred, the Elk, the Rain-deer, the Stag of Canada, &c. 4. The Goat-kind. 5. The Gazella or Antelope. 6. The Squirrel-kind. 7. The Rat-kind. By all which Lists, you may plainly perceive, what good grounds you have for forming your notion; since there are so many Animals that are carnivorous, that have no Colon or Caecum at all; and, on the other hand, how vast a number are there that are not carnivorous, that have either a Colon or Caecum, or both. But notwithstanding all this, we may be mistaken in the Conclusion we may be apt to draw from hence: and may as well argue, that because the Neat-kind, the Stag-kind, the Goat-kind, and the Sheep-kind, that live on Herbage, have four stomachs, therefore those that have not four stomachs, were not design'd by Nature to be be Granivorous. Now the Horse-kind, the Hare-kind, &c. have but one stomach, and yet their Food is Grass. And the case is here the more remarkable, because the stomach is a part more principally concerned in digesting the Food. The Intestines are for separating the Chyle and carrying off the Faeces. Yet we observe even in Animals, that live on the same sort of Food, that their stomachs are very different. One would therefore be more apt to think, that for digesting the variety of Food, and what is of a different nature, that the Organ that is to perform it should be different too. Yet we find that the stomachs of Animals that live upon Flesh, of others that live upon Fruits, and others that live upon Grass, &c. to be much alike; that 'twould be difficult to assign any difference between them. If therefore we cannot make a conclusion from the structure of the stomach, what food is most natural to an Animal, much less one would think from the Colon or the Cæcum; those parts of the Ductus Alimentalis that are remote from the stomach; and being so, seem rather as a Cloaca, for the reception of the Faeces, than otherwise, of any great concern in digesting the food, or distributing the chyle. It would be infinite should I expatiate upon Natures great Variety, in the formation of the structure of this Ductus Alimentalis in different Animals; and even where we may observe much the same sort of food, yet we do not always find the same structure, though her Intendment be the same, in digesting the Food, distributing the Chyle, and ejecting the Faeces in all of them. But herein she shews her great Wisdom, in attaining the same end, different ways. Had chance any concern herein, we should not observe that constant regularity in the same species, nor variety in different, where the action is so much the same. But here perhaps you will say, I begin to Interlope; I shall therefore now draw toward a conclusion. Since Man therefore hath all manner of Teeth, fit for preparation of all sorts of Food, before it be convey'd to the Stomach; I should rather think, that Nature did intend he should live upon all; or at least is so Bountiful as not to deny him any, or stint him to one sort only. So in like manner, since the Organ here in Man, is fitly adapted for Digesting all sorts of Food, I should rather incline to conclude, that therefore Nature intended all sorts for him: Which God Almighty assures us he did, in the Text you have quoted, Gen. 9. v. 3. Every moving thing that liveth shall be meat for you, even as the green Herb have I given you all things. But perhaps you may expect I should give you some Instances in Brutes, where it doth not hold, that all Carnivorous Animals have no Colon or Caecum, though, as to Man, the case may be different. Now the Cariguenya or Opossum (whose Anatomy I have given in Philosoph. Trans. No. 239) had a long Colon, though not cellulated, and a large Caecum, that received all the Faeces as they pass down; Yet this Animal feeds on Poultry and Birds. And I have a Male Opossum now by me, that feeds on nothing but Flesh. On the other hand, the Hedge-hog or Urchin, that hath no Colon or Caecum, and therefore, by your rule, should be Carnivorous, feeds on Roots, Fruits, Herbs, &c. and not on Flesh. Hogs likewise, that have both a Colon and Caecum, will feed upon Flesh greedily enough, when they can meet with it; though their ordinary Food be of another kind. And a Rat and Mouse, that have a large Caecum, but no Colon, feed upon Bacon, as well as Bread and Cheese. But, if what Helian tells us (Hist. de Animal. lib. 17. cap.45.) can be relied upon, you have an instance in the Neat-kind also. For he assures us, Ἀγεωταῖοι δὲ ἀνάστησαν τῶν ἐρων οἱ τῶν ἀλεππων ταῦται, καὶ καλύμνους σαρκοφάγους. So likewise in the same Book, cap. 25. he mentions Horses and Sheep that fed upon Fish. But these stories, sup- suppose, he hath taken up from the Indian Historians whose Credit I have sufficiently examined in my Discourse concerning the Pygmies of the Ancients; and shall therefore lay no stress upon them. Your Observation therefore as to Brutes, though it may hold for the most part true, yet it is not Universal. And, as all other Rules, may have some Exception. I am, Sir, with the greatest Respect, Your most Obedient Humble Servant, Edward Tyson. A second Letter of Dr Wallis to Dr Tyton, on the same subject. Oxford, Jan. 23. 1701. SIR, I Received (some days ago) your Obliging Letter, (in Answer to mine about ηεωραγία, or Feeding on Flesh;) and Read it with great Content. I should (with more earnestness) beg your pardon, for having given you the trouble of so Elaborate and Judicious a Discourse, if I did not think I have served the Publick therein; and that it may give as ample satisfaction to the Learned World (if you will permit it to be published) as it hath done to me. I am not fond of advancing a New Hypothesis, contrary to the common sense of mankind. I did but suggest, to your consideration, a matter of Fact; without being Positive, what Conclusion to infer from it. And I should not have ventured so far, if Gassendus had not first broke the Ice; upon a Notion not much more considerable than that of mine. Wherein you have fur- nished me with a great number of Instances, beyond those few I could suggest, or could expect from any other hand. Upon the whole matter, I think your sentiments to be much the same with mine. I am inclined to think, That all Nations (as well before as since the Deluge) have used to feed on Flesh. Which is a strong Presumption (as you well observe) that to feed on Flesh (duly prepared) is not wholly Unnatural for Mankind. On the other hand; I believe you think (as I do) that Raw Flesh is not a Natural Food for our Bodies. I do not know that any Nation have (of choice) used to feed on Raw Flesh; unless in cases of Extremity, or when they have not the Convenience of Preparing it by previous Coction, or somewhat equivalent. (For I put a great difference between Raw Flesh (which is the common Food of what we call Carnivorous Animals,) and Flesh duly prepared for our Food.) If any there be that (of choice) feed on Raw Flesh, I look upon it as a Case Anomalous; like that of the Lamb mentioned by Gassendus; and the Horse (you mention) that Eats Oysters. I may add, the Rat eating Bacon, for want of other Food, (which yet is not quite void of Coction;) and the Swine sometimes eating Poultry. Which latter, I do not take to be purely Natural; but rather the effect of an Appetite Depraved by Custome; because much of the Hog-wash we give to Swine, ariseth from the Coction of Flesh for our own use; which doth inure the Swine (a Voracious Animal) to the Taste of Flesh, and makes it familiar to them. But Flesh, duly prepared for our Food, I look upon as a thing very different from Raw Flesh, and which may be proper Food for Man; if (and so far as) it agrees with our Health: (which caution is to be observed, as to other Food, as well as Flesh.) And this I refer to the care of the Physician and the Apothecary, rather than the Cook and the Confectioner: fectioner: For these do oft comply with the Wantonness of the Palate, rather than the Health of the Body. I leave it to you to consider, from what Reason, and for what Use, the passage of Flesh through the Ductus Alimentalis, should (ordinarily) be more Quick, and that of Herbs more Slow; (For that seems to be the cause, the Colon making the Way Longer, and the Passage Slower;) and, in what Degree it is so. I say Ordinarily; because, in case of Catharticks (or what is equivalent) the speed is quickened. And, again; When as Nature seems to have (originally) designed, in Man, a large Caecum, as in some other Animals, (and which, if I mistake not, is, in the Fetus, larger, in proportion to the rest of the Intestines, than in persons Adult,) How it comes to pass that it is now of little or no use; but shrinks up into an Appendix Vermiformis; Whether or no this may partly proceed from our Feeding so much on Flesh; which will not admit so great a Remora, as a large Caecum may occasion in other Animals. I conclude, with hearty Thanks for your great Pains; And am, SIR, Your very humble Servant, John Wallis.