312 Dr. Granville on a mal- conformation of 
tance between the ova, which distance cannot exist without 
two distinct momenta in the propulsion of the two ova from 
the ovarium into the oviduct. 
What obtains in cases of twins, must also take place where 
three, four, or even six children have been brought forth at one 
birth ; three ova being formed in each ovarium, so near to each 
other, that the three points at which they were expelled, must 
have all come within the long continued grasp of the fimbriated 
bodies. Indeed it is possible, that the separation of more than 
one ovum at a time, from one ovarium, or from both, takes 
place oftener than we are led to believe, from the mere calcu- 
lation of the number of complex labours. For if the ova pass 
into the uterus even without copulation ; it is no bad logic to 
suppose, that some will occasionally go through that viscus, 
which are never impregnated at all. This is indeed proved by 
a greater number of corpora lutea being found in the ovaria of 
some females, than corresponds to the number of young they 
have produced ; a doctrine, which I first read in your valuable 
communication in the Philosophical Transactions, “ On the 
Passage of the Ovum in JVomen , &c.” when you last year gave 
me the paper to carry to Monsieur Cuvier, and which I was 
happy to find afterwards immediately adopted by that eminent 
naturalist, in his course of lectures on generation. 
These remarks lead to another, and the last consideration 
on the present subject; namely, the existence of separate 
placentae in cases of twins, or even triplets; which unless 
viewed in its true light, will make us run the risk of render- 
ing that obscure, which in the process of generation seems 
perhaps the most intelligible. Instances of such occurrences 
are very numerous ; they have been often mentioned by 
