Characters of Hybrids 
Darwin’s view that domestication tends to elimi- 
nate sterility; but it is doubtful if this can be 
upheld. The hybrid between the Muscovy duck 
(Cazrena moschata) and common duck is usually, 
at all events, sterile, like that between the pigeon 
and dove; yet all these birds have been long 
domesticated. The hybrid between the fowl and 
the guinea-fowl is likewise barren, nor has the 
long domestication of the horse and ass lessened 
the sterility of the mule. 
Some facts may be noted respecting the 
characters of hybrids. In the first place, it is 
important to notice that the characters of the 
hybrid vary according to the sexes of the species 
concerned ; thus, the “hinny,’ which is bred 
from a horse and a she-ass, is a different animal 
from the true ‘“‘mule,” which is bred from the 
jackass and mare, and is inferior to it. 
Similarly, Mr G. E. Weston, a great authority 
on British cage-birds and their hybrids, informs 
us that when hybrids are bred from a male canary 
and a hen goldfinch or siskin—contrary to the 
almost universal practice of using the hen canary 
for crossing—the progeny are inferior in size and 
colour to the hybrids obtained in the ordinary 
way. 
Hybrids, in animals at all events, differ from 
crosses between mutations or colour-variations 
in not exhibiting the phenomenon of alternative 
inheritance ; they do not follow one parent or 
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