177 
Dissection of an Hermaphrodite Dog. 
the time of impregnation, it may in some measure account for 
the free-martin occurring when two young ^re to be impressed 
with different sexes, at one impregnation ; which must be a 
less simple operation, and therefore more liable to a partial 
failure, than when two or any greater number of ova are im- 
pressed with the same sex. It may also account for twins 
being most commonly of the same sex ; and, when they are of 
different sexes, it leads us to inquire whether the female, when 
grown up, has not in some instances less of the true female cha- 
racter than other women, and is not incapable of having children. 
It is curious, and in some measure to the purpose, that in some 
countries, nurses and midwives have a prejudice, that such twins 
seldom breed. 
This view of the subject throws some light on those cases 
where the testicles are substituted for the ovaria ; since, when- 
ever the impregnation fails in stamping the ovum with a per- 
fect impression of either sex, the part formed will neither be an 
ovarium nor a testicle, sometimes bearing a greater resem- 
blance to the one, sometimes to the other ; and may, according 
to circumstances, either remain in the natural situation of the 
ovaria, or pass into the situation proper to the testicle, whether 
it is the scrotum of the male, or the labia pudendi of the 
female. 
EXPLANATION OF THE PLATE. (Tab. IV.) 
The plate consists of two figures, which represent the ante- 
rior and posterior view of the organs of generation, in the her- 
maphrodite dog. 
