ole Ewart— Variation : Germinal and Environmental. 
equally represented. Had the germ-cells in the case of the pigeons succeeded in 
developing apart, they would have given rise to twins, one black like the male 
parent, the other the image of the white female parent. 
2. The offspring may resemble one of the parents. This is frequently the 
case when wild members of a species are crossed with tame varieties of the same 
species, ¢.g. when wild and tame rabbits, rats, and mice are intercrossed. The 
same result is sometimes obtained by crossing members of two distinct genera. 
When the orchid Zygopetalum Mackayt is crossed with certain species of Odonto- 
glossum (eg. Pescatored and erispum), the hybrids are “ Zygopetalum Mackayi,” 
pure and simple, without any trace of the peculiar structure of the pollen parent 
in any case.* 
Very often one tame variety is prepotent over another. I have a yellow and 
white (skewbald) pony that two years ago produced to a bay pony a foal, which in 
its colour, disposition, and gait is the image of herdam. When quite young, this 
pony produced to a sire, more prepotent than herself, a dark dun-coloured foal. 
That Galloway are prepotent over Highland cattle has already been mentioned. 
In the same way, a silver-grey rabbit proved prepotent overa Himalaya doe—of 
thirty-nine young, all resembled in colour, though not in make, the silver grey 
buck. So in pigeons, one breed of a given colour may prevail. A “restored” 
rock pigeon proved on one occasion prepotent over a barb, and a white fan, the 
offspring of two blue fans, produced a perfectly white bird when mated with his 
own dam. 
We often account for the prepotency of one genus, species, variety, or race, by 
saying it belongs to an older type. This explanation, however, is sometimes at 
fault, for quite a new type may be prepotent over an old one. Some time ago 
I saw in Kent a “calico” or “painted” mule spotted all over like an Indian 
“painted” (pinta) pony. As arule mules are more like the ass sire than the horse 
dam, but when the dam is a ‘“‘sport” some of the hybrid offsprmg may fairly 
accurately reproduce her recently acquired peculiarities, such as spots or large 
blotches. Again, a dark variety of the peppered moth has recently largely 
displaced the older and lighter variety over a considerable part of England. 
In these cases the result evidently depends on the germ-plasm of one of the 
parents being overpowering, able to dominate the germ-plasm provided by the 
other parent—on the germ-plasms being antagonistic or at least incapable of 
blending. 
Hence it follows that in some cases the prepotency may be regarded as 
quite independent of the environment, in eg. the wild rabbit, rat, and mouse, 
while, in others, it may, to a considerable extent, depend on the maturity of 
the germ-cells. 
* Hurst, Vature, Dec. 22, 1898. 
