122 PHILOSOPHICAL TRANSACTIONS. [ANNO 1 7^7- 



by alledging, that if the tube had not been obliterated till after coition, the semen 

 or its power might have affected the ovary by actual contact; and the product of 

 conception might have been more complete. And in support of this idea, he might 

 adduce the result of an experiment said to have been made by Nuck, in which he 

 made an extra-uterine case in a bitch, by tying one of the tubes 3 days after 

 coition. 



These objections have at least speciousness to recommend them to our notice; 

 but it is from experiment alone that we can determine whether they have any 

 solidity. To the first difficulty I reply, that my experiments were not made under 

 the same circumstances that Nuck's is said to have been; therefore, giving him full 

 credit for what he has advanced, a similarity of result cannot be expected. But it 

 is painful to me to differ from any writer of character in the statement of a fact, 

 where the truth is equally accessible to us both ; and notwithstanding the respect I 

 willingly bear towards a name that has both acquired and deserved considerable 

 reputation, I must confess that it appears to me highly problematical, whether this 

 celebrated experiment be a reality, or only an ingenious device. But some facts, 

 which it will be soon in order to relate, will show, I think very clearly, that I rest my 

 suspicion on fair grounds. In the mean time I feel it incumbent on me to reply to 

 the general principle of the objection, and to determine by experiment how far it is 

 deserving attention. 



Now, if there be any validity in the objection, it should necessarily follow, that 

 if an opportunity was given for the semen to pass by the tubes to the ovaries; we 

 might, by opening an animal at a proper time after coition, detect some disposition 

 in the fimbriated extremities of the tubes to apply the semen, by first approaching, 

 and afterwards embracing the ovaries; and this action ought, according to the com- 

 mon theory, to take place before the usual sign of conception is at all evident on 

 those bodies, when the rabbit is somewhat apparent in 6 hours, but unequivocally 

 marked in 12. 



Again, admitting the probability of it, we are led to inquire by what power the 

 semen can be conveyed to such a distant part. It must be either by the male, vi 

 jaculationis, or by muscular power in the tubes, analogous to a peristaltic motion. 

 If it were by the first mode, the conveyance would be instantaneous ; but in the 

 latter, some little time seems necessary to allow the tubes to be affected by the 

 stimulus preparatory to their peristaltic action. Perhaps this question may receive 

 some light from the sacrifice of a few animals, at different periods between the 

 coitus and the first visible effects of impregnation ; and I considered it by no means 

 inapposite to the subject, to determine whether these conjectures were authorized 

 by any visible changes, either in the condition or situation of the tubes. But the 

 fruits of this inquiry will appear by the following experiments. 



Expers. A female rabbit in high season was admitted to the male, and in a few 

 minutes afterwards the ovaries and tubes were brought into view ; but the fimbriae 

 were in their natural situation. As soon as proper rabbits could be procured, I re- 

 peated this experiment on 2 others, with precisely the same consequence. These 



