CHAPTER X 
OTHER KINDS OF HYBRIDIZING 
Blended Inheritance 
WE have seen in the cases that come under Mendel’s law that 
the contrasted characters do not both develop at the same time, the 
offspring in the first generation being often like one or the other 
parent. Yet in some of these cases there is evidence that the 
dominant character may be weakened by the recessive one. We 
may now consider cases in which the contrasted characters of 
the two parents fuse or blend completely in the offspring. Cases 
of the sort are found not only between races, varieties, and elemen- 
tary species, but this method of union has long been supposed to 
be a characteristic feature of hybridization when Linnzan species 
are crossed. 
The most familiar and striking case of fusion or blending of 
two characters is found in the mulatto — the result of union of a 
white and a black individual. The mulatto breeds true in all 
successive generations, neither the white nor the negro ever 
appearing again in the pure form. If the mulatto again crosses 
with the white stock, the dark color is again lessened, but even 
after several generations of crossing with the white stock traces 
of the dark pigment remain. Conversely crosses between the 
mulatto and the black race produce ever increasing shades 
of darkness in successive generations of offspring. Not only 
the color, but the character of the hair also shows a tendency 
to blend in the hybrid. 
Flourens made crosses between the domestic dog and jackal, 
the latter being, however, ‘“‘prepotent.” The horse and the ass 
give the mule, that is intermediate in many respects, but the 
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