182 Dr. Haighton's experimental Inquiry 
fact, where the truth is equally accessible to us both ; and not- 
withstanding 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 soon be in order to relate, 
will show (I think very clearly) that I rest my suspicion upon 
fair grounds. In the mean time I feel it incumbent on me to 
reply to the general principle of the objection, and to deter- 
mine by experiment how far it is deserving attention. 
Now, if there be any validity in the objection, it should ne- 
cessarily 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 common theory, to take 
place before the usual sign of conception is at all evident on 
those bodies, which in the rabbit is somewhat apparent in six 
hours, but unequivocally marked in twelve. 
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 mus- 
cular power in the tubes, analogous to a peristaltic motion. If 
it were by the first mode, the conveyance would be instanta- 
neous ; 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; 
