concerning Animal Impregnation. 185 
be formed, while by obliterating the tube ante coitum nothing 
more than corpora lutea were seen, it furnished an argument 
of no inconsiderable force in favour of impregnation by imme- 
diate contact ; but if on the contrary, corpora lutea only were 
found, then such experiments would give additional force to 
the arguments stated in a former part of this section. 
EXPERIMENT. 
One of the tubes of a rabbit was divided half an hour post 
coitum , and the wound closed as before. She was kept a fort- 
night, that I might know the result ; but there were no marks 
of impregnation on either side. 
Though a failure of impregnation has been very common in 
experiments connected with the mutilation of these parts, I ap- 
prehended that the derangement in the present instance pro- 
ceeded from some disturbance given to the procreative opera- 
tions in their commencement, and therefore determined in the 
next trial to wait a few hours, the better to avoid this. 
EXPERIMENT. 
I repeated the operation on two other rabbits, in one at four, 
■and in the other at six hours after coition. On inspecting the 
parts at the end of a fortnight, the first was not impregnated, 
but the last was. In this there were four corpora lutea in the 
right side, answering to the same number of foetuses in the 
cornu uteri of that side; but on the left or imperfect side, there 
were three corpora lutea without foetuses. The corpora lutea on 
both sides were cut open, but not the slightest difference could 
be detected. 
Now, if the contact of the semen with the ovaries in any 
MDCCXCVII. B b 
