120 PHILOSOPHICAL TRANSACTIONS. [ANNO 17Q7. 



those which had not; I determined to make a trial of one of this description, with 

 a view to compensate for my former disappointment. 



Exper. Being furnished with 1 of this kind, and from which the young had 

 been taken away 3 weeks at the age of 10 weeks, which, together with the month 

 of gestation, amounted in the whole to 4 months from the last conception, I made 

 this the subject of the experiment. Now, at this distance of time, it is not very 

 probable that the ovaries should retain very evident vestiges of the preceding con- 

 ception : but as it was a point of too much importance to be left in doubt, I deter- 

 mined to satisfy myself by ocular examination, which, by a little management, was 

 effected. The traces of corpora lutea were far from being evident, so that there 

 was no danger of confounding them with any recent mark that might happen. 

 The tube on one side was cut through as before, but to my unspeakable mortifica- 

 tion this rabbit was as barren as the former, though tried several times during the 

 space of 3 months. The generative organs were examined after death, and the 

 appearances corresponded with those of former experiments. 



In this case, as well as in a former, I had an opportunity of comparing the 

 shrunk state of the ovaries after death, with the plump and healthy condition before 

 the mutilation; and it affords an additional proof of that sympathetic connexion, 

 or consent, between one part of the generative organs and another; and shows 

 that in the production of a new animal, the co-operation of different parts is ne- 

 cessary; and further, that if the assistance of one part is wanting, the others, as 

 if governed by a principle of intelligence, cease to continue their important work. 

 But I was still in a state of suspense with regard to the end for which these expe- 

 riments were instituted; and such an uninterrupted succession of failures on a point 

 so essential to my present inquiries, I confess tended but little to animate me in the 

 pursuit. I was beginning to suspect that the barrenness consequent to the division 

 of only one of the tubes, was as determined a law in the economy of these parts, 

 as it seemed to be in those cases where both tubes were cut through ; and that 

 nothing could prevent this sterility; but my contemplations were directed into an- 

 other channel by the following experiment. 



Exper. Having procured another rabbit, nearly under the same circumstances 

 as the last, I operated precisely in the same mode, and had equal evidence too con- 

 cerning the condition of the ovary. The result of this experiment was successful; for 

 on admitting the maleto her about 1 month from the operation, she betrayed no reluc- 

 tance, and became impregnated. Ten days afterwards she was killed, and opened. 

 Both ovaries retained their primitive plumpness, and manifested the evidences of 

 impregnation. These evidences are the presence of corpora lutea, bearing the 

 same precise characters as I have demonstrated in the former part of this essay. 

 Those seated in the ovary of the mutilated side did not differ in any respect from 

 the same bodies on the perfect side: but they were unattended with foetuses; 

 whereas in the perfect side, there were as many foetuses as corpora lutea. 



