concerning Animal Impregnation. 
179 
EXPERIMENT. 
Having procured another rabbit, nearly under the same cir- 
cumstances as the last, I operated precisely in the same mode, 
and had equal evidence too concerning the condition of the 
ovary. The result of this experiment was successful ; for on 
admitting the male to her about one month from the operation, 
she betrayed no reluctance, and became impregnated. Ten 
days afterwards she was killed, and opened. Both ovaries re- 
tained 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 demon- 
strated 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 
As this experiment had succeeded, I examined the divided 
tube with attention, to satisfy myself whether its canal was 
obliterated ; and of this I had the clearest proof ; for it would 
not allow quicksilver, nor even air to pervade it. 
Now here is matter for reasoning. Both ovaries, it seems, 
bear unequivocal proofs of impregnation, but foetuses are found 
only on one side. 
Now, on what principle shall we explain these phenomena ? 
It is certain that neither semen nor the aura seminalis could 
have touched the left ovary, and yet it bears the most unequi- 
vocal marks of recent impregnation. It must depend on some 
other cause than the actual contact of semen. 
But an important subject for investigation here presents 
A a 2 
