172 Dr. Haighton's experimental Inquiry 
question would be rather extraneous to my investigation, I 
must decline any further disquisition. 
The difficulties which were opposed to the conveyance of the 
semen by the tubes, were, as we should suspect, intended to 
prepare the way for a different explanation ; therefore physio- 
logists, by a very natural transition of thought, were led to 
suppose that the presence of semen in the vagina alone was 
sufficient to account for impregnation. 
In order to give support to this opinion, cases were adduced, 
in which, from some anatomical peculiarities, it seemed almost 
impossible that the fecundating fluid could be conveyed into 
the uterus ; and yet in several of these cases impregnation had 
really taken place. It would be digressing too much to state 
the facts in detail, seeing that in this inquiry I deduce nothing 
from them ; nor would such statement solve the problem be- 
fore us. The facts are already in the possession of physiolo- 
gists, but are not admitted as satisfactory proofs. Those who 
hold the contrary opinion, either cavil at the accuracy of the 
statement, or draw a different conclusion; therefore to attempt 
conviction by these materials would be to engage in the service 
of forlorn hope. It remains then to try whether by a patient 
experimental investigation, we can make such an accession of 
new facts to our present stock of knowledge as will enable us 
to unloose this Gordian knot. This attempt naturally leads us 
to review the two points of the question, viz. Is the passage of 
the semen by the tubes to the ovaries , essential to impregnation ? 
If not, what other means are employed ? 
If it be true that the fecundating fluid must pass by the tubes 
to the ovaries before impregnation can take place, ought it not 
