After having exerted every effort to establish, by reasons drawn from comparative anatomy, that the testicles of viviparous females are real ovaries, De Graaf explains how the eggs are loosened from the ovaries and fall into the horns of the matrix; he then relates what he observed in a rabbit, which he dissected half an hour after copulation. The horns of the matrix, he says, were more red than before, but no other change in the rest of the parts: there was also no appearance of any male seed, neither in the vagina, matrix, nor horns of the matrix. Having dissected another six hours after copulation he observed the follicules, or coats, which he supposes contained the eggs in the ovary, ware become red, but found no male seed either in the ovaria or elsewhere. He dissected another twenty-four hours after copulation, and remarked in one ovarium three, and in the other five follicules that were changed, the transparency being become dark and red. In one dissected twenty-seven hours after copulation he perceived the horns of the womb had become more red and strictly embraced the ovaries. In another, that he opened forty hours after copulation, he found in one of the ovaries seven, follicules, and in the other three that were changed. Fifty-two hours after copulation he examined another and found one follicle changed in one of the ovaries and four in another, and having opened these follicules he found a glandular liquor, in the middle of which there was a small cavity, where he did not perceive any liquor, which made him suppose that the transparent liquor, commonly contained in the follicules, and which, he says, is enclosed in its own membranes, might have been separated by a kind of rupture: he searched after this matter in the passages, and in the horns of the matrix themselves, but he found none; he only perceived that the internal membrane of the horns of the matrix was very much swelled. In another, dissected three days after copulation, he observed that the superior extremity of the passage, which communicates with the horns of the matrix, strictly embraced the ovaries; and having separated it he perceived three follicules, longer and harder than usual. After searching with the greatest attention the passages above-mentioned he found in the right passage one egg, and in the right horn of the matrix two more, not bigger than a grain of mustard-seed: those little eggs were each closed in double membranes, and the inner one was filled with a very limpid liquor. Having examined the other ovarium he found four follicules that were changed, three of which were white and had a little liquor within them; but the fourth was of a darker colour, and contained no liquor, which made him judge that from this the egg had been separated. Pursuing his enquiries he found an egg in the superior extremity of the other horn, and exactly like those he had discovered in the right one. He says that the eggs which are separated from the