XXVIII. Fifteen days after I opened another bitch that had been in heat seven or eight days, but had not received the dog. I found the testicles contiguous to the extremities of the horns of the matrix; these horns were very long, their external tunic surrounded the testicles, and they appeared covered with that membrane like a cowl. In each testicle I found a glandular body in its full maturity. The first was half open, and there was a passage which penetrated into the testicle, and which was replete with seminal liquor; the second was somewhat more large and prominent, and the orifice, or canal, which contained the liquor was below the nipple. I took these two liquors, and having compared them, found them perfectly alike. The seminal liquor of the female is at least as liquid as that of the male. Having afterwards examined the two liquors with the microscope, I perceived the like moving bodies, (_fig. 10._) and the same phenomena, as in the seminal liquor of the other. I saw besides many globules which moved very briskly, and endeavoured to disengage themselves from the mucilage that surrounded them: there was a great quantity of them as in the seed of the female. XXIX. From these glandular bodies I pressed out all the liquor, and having collected it, I found enough to last for four or five hours observations. I remarked that it deposited somewhat to the bottom, or at least began to thicken. I took one drop of this, which was thicker than the rest, and having put it on the microscope, perceived that the mucilaginous part of the seed was condensed, and formed a continued net-work. On the external border of this net-work, there was a torrent, or current, composed of globules, which moved with rapidity. These globules were lively, active, and appeared to be disengaged from their mucilaginous covering, and their tails. This stream perfectly resembled the course of the blood in small transparent veins; for they appeared not only to be animated by their own powers, but also to be impelled by a common force, and constrained to follow in a herd. From this experiment, and the XIth and XIIth, I concluded, that when the fluid begins to coagulate and thicken, these active globules break and tear their mucilaginous coverings, and escape by that side where the liquor remains most fluid. These moving bodies had then neither threads nor tails; they were for the most part oval, and appeared to be flat at the bottom, for they had no rolling motion.