Page:The Works of William Harvey (part 1 of 2).djvu/592

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.
492
ON GENERATION.

look like a pair of bracelets composed of so many amber beads strung upon a thread. The conception of the hare bears a strong resemblance to an acorn, the placenta embracing the embryo like a cup, and the humours inclosed in their mem- branes depending like the gland or nut.

EXERCISE THE SEVENTIETH.

Of the conception of the deer in the course of the month of December.

In the beginning of December the foetus is seen larger, every way more perfect, and the length of the finger. The heart and other viscera which formerly hung externally are now concealed within the cavities of the body, so that they can no longer be seen without dissection.

The conception, or ovum, by the medium of the five carun- cles which we have already spoken of as present in either cornu, is now in connexion with the uterus at an equal number of points ; still the union is not so strong but that a very slight rather than a great effort suffices to break it. When the conception is detached, we perceive points or depressions on the surface of the chorion at the places where the adhesions to the uterus had existed, these spots being further covered with a certain viscid and wrinkled matter, as if this had been the bond of union between the mother and the ovum. Thus have we the nature and use of these caruncles made known to us : seen in the first instance as fungi or excrescences growing from the sides of the uterus, they are now recognized in connexion with the conception, as standing instead of the placenta or ute- rine cake in the human subject, and performing the same office. These caruncles are in fact but as so many nipples, whence the embryo by means of its umbilical vessels receives the nourish- ment that is supplied by the mother, as shall be clearly shown by what is to follow.

The size and capacity of the uterus, by which name we understand the cornua, or place occupied by the conception, is increased in proportion to the growth of the embryo ; in such-