274 
HYBKIDISM. 
Chap. VIII. 
hybrids: Grartner states that mongrels are more liable 
than hybrids to revert to either parent-form; but 
this, if it be true, is certainly only a difference in 
degree. Gartner further iusists that when any two 
species, although most closely allied to each other, are 
crossed with a third species, the hybrids are widely 
different from each other ; whereas if two very distinct 
varieties of one species are crossed with another species, 
the hybrids do not differ much. But this conclusion, 
as far as I can make out, is founded on a single experi¬ 
ment; and seems directly opposed to the results of 
several experiments made by Kolreuter. 
These alone are the unimportant differences, which 
Gartner is able to point out, between hybrid and 
mongrel plants. On the other hand, the resemblance 
in mongrels and in hybrids to their respective parents^ 
more especially in hybrids produced from nearly re¬ 
lated species, follows according to Gartner the same 
laws. When two species are crossed, one has some¬ 
times a prepotent power of impressing its likeness 
on the hybrid ; and so I believe it to be with varieties 
of plants. With animals one variety certainly often has 
this prepotent power over another variety. Hybrid 
plants produced from a reciprocal cross, generally re¬ 
semble each other closely; and so it is with mongrels 
from a reciprocal cross. Both hybrids and mongrels 
can be reduced to either pure parent-form, by repeated 
crosses in successive generations with either parent. 
These several remarks are apparently applicable to 
animals ; but the subject is here excessively compli¬ 
cated, partly owing to the existence of secondary sexual 
characters; but more especially owing to prepotency 
in transmitting likeness running more strongly in one 
sex than in the other, both when one species is crossed 
with another, and when one variety is crossed with an- 
