Page:The Works of William Harvey (part 1 of 2).djvu/539

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ON GENERATION.
439

any fluid that thus gained access to the fauces must needs have been swallowed ; for it is certain that whatever passes the root of the tongue and gains the top of the oesophagus, cannot be rejected by any animal with a less effort than that of vomiting. This fact is acted upon every day by veterinary practitioners, who in administering medicated drinks and pills or boluses to cattle, seize the tongue, and having put the article upon its root beyond the protuberant part, the animal cannot do other- wise than swallow it. And if we make the experiment our- selves, we find that a pill carried between the finger and thumb as far as the root of the tongue and there dropped, immedi- ately the action of deglutition is excited, and unless vomiting be produced the pill is taken down. If the embryo swimming in the fluid in question, then, do but open his mouth, it is ab- solutely necessary that the fluid must reach the fauces ; and if the creature then move other muscles, wherefore should we not believe that he also uses his throat in its appropriate office and swallows the fluid?

It is further quite certain that in the crop of the chick, and the same thing occurs in reference to the stomach of other embryos there is a certain matter having a colour, taste, and consistence, very similar to that of the liquid mentioned, and some of it in the stomach digested to a certain extent, like co- agulated milk ; and further, whilst we discover a kind of chyle in the upper intestines, we find the lower bowels full of sterco- raceous excrements. In like manner we perceive the large intestines of the foetuses of viviparous animals to contain excre- ments of the same description as those that distend them when they feed on milk. In the sheep and other bisulcated animals we even find scybala.

Towards the seventeenth day we find dung very obviously near the anus of the chick; and shortly before the extrusion I have seen the same matter expelled and contained within the membranes. Volcher Coiter, a careful and experienced dissector, states that he has observed the same thing.

Wherefore should we doubt, then, that the foetus in utero sucks, and that chylopoiesis goes on in its stomach, when we find present both the principles and the recrementitious pro- ducts of digestion ?

And then, when we find the bladder both of the bile and the