XI PHENOMENA OF ORGANIC NATURE 401 
that although you have the same elements in the 
- experiment in each case, the offspring is entirely 
different in character, according as the male influ- 
ence comes from the ass or the horse. Where the 
ass 1s the male, as in the case of the mule, you 
_ find that the head is like that of the ass, that the 
_ ears are long, the tail is tufted at the end, the feet 
are small, and the voice is an unmistakable bray ; 
these are all points of similarity to the ass; but, 
_ on the other hand, the barrel of the body and the 
cut of the neck are much more like those of the 
mare. Then, if you look at the hinny,—the result 
_ of the union of the stallion and the she-ass, then 
_ you find it is the horse that has the predominance; 
_ that the head is more like that of the horse, the 
; ears are shorter, the legs coarser, and the type is 
_ altogether altered ; while the voice, instead of being 
. a bray, is the ordinary neigh of the horse. Here, 
_ you see, is a most curious thing: you take exactly 
the same elements, ass and horse, but you combine 
® the sexes in a different manner, and the result is 
: modified accordingly. You have in this case, how- 
_ ever, a result which is not general and universal— _. 
there is usually an important preponderance, but 
t not always on the same side. 
. Here, then, is one intelligible, and, perhaps, 
“necessary cause of variation: the fact, that there 
“are two sexes sharing in the production of the off- 
“spring, and that the share taken by each is differ- 
ent and variable, not only for each combination, 
; VOL, II DD 
