Page:The Works of William Harvey (part 1 of 2).djvu/658

 brane, moreover, is loaded with vessels." It is, in fact, the chorion; so called from the conflux or multitude of veins. I have often observed ova of this kind escape in the second and third month; they are frequently decomposed internally, and come away gradually in the form of a leucorrhoeal discharge, and thus the hopes of the parent are lost.

Another reason why these humours cannot be sweat and urine, is, that they exist in such abundance at the very beginning;—for the purpose, no doubt, of preventing the body of the fœtus from coming in contact with the adjacent parts when the mother runs, jumps, or uses violent exertion of any kind.

Added to which, many animals never sweat at all, (and we must remember what is said by Aristotle, "that all creatures which swim, walk, or fly," I will add serpents and insects, whether viviparous or oviparous, or generated spontaneously, "are produced after the same manner,") as is the case with birds, serpents, and fishes, which neither sweat nor pass urine. The dog and cat also never sweat; neither in fact does any animal in which the urinary secretion is very abundant. Besides, it is impossible that urine can be passed before the kidneys and bladder are formed.

Moreover, and this is the strongest argument that can be brought forward, those humours can never be excrementitious into which so many branches of the umbilical vessels are distributed by means of the chorion; these vessels, in fact, in this manner taking up nourishment, (as it were from a large reservoir,) and then conducting it to the fœtus.

Besides what need is there of an allantois, if the fluid within the chorion is urine? And if that in the amnion is sweat, why does Nature, who contrives all things well, ordain that the fœtus should float about in its own excrement? And why, too, should the mother (as is the case with some animals) immediately after birth, so greedily devour the excretions of its own offspring, together with the containing membranes? Some have even observed that if the animal fails to eat up these matters it does not give its milk freely.

Notwithstanding these arguments, it may possibly be ima-