130 PHILOSOPHICAL TRANSACTIONS. [ANNO 1797. 



so as to pout or project, at last, like the nipple in a woman's breast. Some hours 

 after impregnation, the calyx and the coverings of the ovaria burst, and the ovum 

 escapes ; may fall into the general cavity of the abdomen, and form an extra-uterine 

 feet us ; but almost always falls into the mouth of the fallopian tube, whose fimbriae, 

 like fingers, grasp the ovarium, exactly at the place where the ovum is to escape. 

 What the appearance of the ovum was, when deprived of its calyx, or when de- 

 scending the fallopian tube was not known. De Graaf discovered this in the fallo- 

 pian tubes of rabbits, in the year 10*72 ; and says, " minutissima ova invenimus, 

 quae licet perexigua, gemina, tamen, tunica amiciuntur;" and then adds, " haec 

 quamvis incredibilia, nobis demonstratu facillima sunt." 



De Graaf had the fate of Cassandra, to be disbelieved even when he spoke the 

 truth ! Dr. Hunter had his doubts ; and the great Haller, of whom I have always 

 6poken in the language of Professor Marrhar, " cujus auctoritas apud me plus valet, 

 quam auctoritas omnium aliorum anatomicorum simul sumptorum," positively de- 

 nies their truth. His words are, " vix liceat admittere" — and afterwards, " denique, 

 quod caput rei est, neque Hartmannus cum experimenta Graffiana iteravit ; neque 

 Valisnerus tot et tarn variis in bestiis ; neque ego in pene centum experimentis ; 

 neque nuperiorum anatomicorum quispiam, vesiculam, quales sunt in ovariis, post 

 conceptionem, aut in tuba vidimus aut in utero !" 



In the beginning of summer 1778? I was conversing with Dr. Hunter on this 

 subject, and said, " I should like to repeat those experiments, now that lectures are 

 over, and that I have the summer to myself." — " You shall make the experiments," 

 said he, " and I shall be at all the expence." Accordingly he carried me to Chelsea, 

 introduced me to a man who kept a rabbit warren, and desired him to let me have 

 as many rabbits as I pleased. I made the experiments ; and shall now lay a copy 

 of my journal, then made, before this Society. 



Exper. I. May 30, 1778. I took a female rabbit, hot, as the feeders term it, 

 that is, ready to be impregnated, and disposed to receive the male. This they find 

 out, not by exposing her to the male, but by turning up the tail, and inverting part 

 of the vagina : its orifice and internal surface are then as black as ink, from the 

 great derivation of blood to these parts. Having run the point of a double-edged 

 dissecting knife through the spinal marrow, between the atlas and dentata, she 

 instantly expired. I preferred this method of killing her, because when the circu- 

 lation stopped, the internal parts would be found, respecting vascularity, exactly as 

 in the living body. On examination some time after, I found the internal parts of 

 generation, exactly in the same state as the external ; that is, as black as ink : the 

 ovaria had, immediately under their external surfaces, a great number of black, 

 round, bloody spots, somewhat less than mustard-seeds. These black spots are the 

 calyces or cups which secrete the ova ; they are extremely vascular ; the ova them- 

 selves are transparent, and carry no visible blood vessels. These calyces, on the 

 expulsion of the ova, enlarge and become yellow, projecting above the external 

 surface of the ovaria, and form the corpora lutea ; a certain mark of conception in 



