Page:The Works of William Harvey (part 1 of 2).djvu/590

 are not unlike crabs' eyes, and I have called them by this name -, but they are smaller, like pendulous warts, glandular and white, sticking within the coats of the uterus, and somewhat excavated towards the conception; otherwise than in the deer, conse- quently, in which the caruncles corresponding to these rather project towards the embryo. These caruncles are gorged with blood, and their inner surface, where they regard the conception, is perceived to be beset with black sanguineous points. The umbilical vessels of the embryo were not yet connected with these caruncles, nor did the conception itself adhere to the uterus.

I find nothing of an allantois, of which something has been said as a tunic distinct from the chorion, in the conception of the ewe. At a later period, indeed, when the embryo is larger, when the ovum or conception has contracted adhesions with the uterus, and the umbilical vessels have penetrated the carun- cles, the chorion extends further, and at its extremities on either side, and as it were in a couple of appendices, there is a certain fluid of a yellow colour, which you might call excre- mentitious, kept separate and distinct.

The human conception scarcely differs in any respect from an egg during the first months of pregnancy. I have observed a clear fluid, like the more liquid white of an egg, to be in- cluded within an extremely delicate membrane. At this time the placenta had not yet appeared, and the entire conception was of the size of a pigeon's, or perhaps a pheasant's egg. The embryo itself, of the length of the little finger nail, and having the form of a small frog, was conspicuous enough. The body was broad, the oral aperture widely cleft, the legs and arms like the stalks of flowers just risen above the ground, the occiput prominent, or rather forming a vesicle appended to the rest of the head, such as we have described the rudiments of the future cerebellum in the chick.

In another human conception of about the fiftieth day, the ovum was as large as a hen's or a turkey's egg. The embryo was as long as a large bean, the head of very large relative dimensions, and dominated by the cerebellum as by a kind of crest. The brain itself was of the consistence of curdled milk. Instead of a cranium there was a coriaceous membrane, in some places cartilaginous, and divided down the forehead to