HYBRIDITY OF THE CERVID. 
As has been already several times intimated, nature seems to 
have established a law of sexual aversion not only among the 
genera, but even among the species of animals and plants, which 
is more or less intense as the dividing line which separates the 
species is more or less pronounced. This aversion is more potent 
with the female than the male, and is more commanding in the 
wild state than when they are brought together in confinement, 
and partial or complete domestication. This aversion is sufficient 
to prevent the commingling of blood of species very nearly 
allied when unrestrained in the wild state, though inhabiting 
abundantly the same wild range, and perhaps this law of sexual 
aversion may furnish as safe a rule as any to distinguish species 
from varieties. Varieties are never constant and distinguishable 
in the same district of country, for the simple reason that there 
is no sexual restraint, which absolutely prevents the maintenance 
of hereditary distinctions which distinguish varieties, and so would 
it happen among species, were there no natural restraint to keep 
them asunder. When such restraint exists which amounts to 
practical prohibition, nature itself declares a purpose to maintain 
a specific distinction. 
If we recognize the law of evolution, then the lines of separa- 
ration of divergent families from an original stock, have become 
so widely separated as to interpose this law of sexual aversion 
between them, and we shall be sure to find permanent physical 
characteristics dependent not upon factitious circumstances, but 
solely on hereditary influences, which, uniting with the law of 
sexual aversion, satisfactorily declares distinct species, where, a 
long time before, when the lines of divergence were less sep- 
arated, they were but varieties, with scarcely impaired sexual 
inclinations for each other. 
We may admit that sexual intercourse sometimes occurs be- 
tween individuals of different species in the wild state, just as 
we see unnatural impulses manifested sometimes in both man 
and brute, but they are so exceedingly rare as to be entitled to 
no influence in the general discussion, and we may if you choose 
agree with those who contend that when such intercourse does 
