DOMESTIC RATS AND MICE 43 



white, strongly ticked with black, a color which breeders 

 seem to find very difficult to secure. These specimens were 

 taken in an isolated locality, where domesticated mice had 

 hardly been heard of, to say nothing of being kept, so there 

 can be no question of their wild ancestry. 



It does not seem strange, therefore, that so many colors 

 should have appeared under domestication. The many 

 shades are inherent in the coats of wild mice, and only the 

 skill of the breeder is required to separate them from ob- 

 scuring influences. 



White mice are the most abundant and commonly kept 

 variety, and probably represent the first important change 

 from the parent form. The white race must have been 

 established without much difficulty, and undoubtedly has 

 been in existence for a great many years. The crossing of 

 whites with wild grays has a tendency to separate the colors, 

 and the varieties which appeared have been fixed by selec- 

 tion. 



Like all fancy mice, whites should be large, with short, 

 velvety coats. The color should be of the purest, with no 

 tendency toward yellowness. The usual white mice have 

 pink eyes, which should be very large. 



Within recent years a black-eyed variety has been intro- 

 duced. These mice are not, of course, true albinos, but 

 are simply the extreme of spotted mice, bred lighter and 

 lighter until the pigment has been entirely eliminated, ex- 

 cept from the eyes. They do not breed perfectly true, a 

 large percentage of the young being more or less spotted. 

 Black-eyed whites are not as yet well known in this country, 

 but are becoming more popular. 



If the stamina of a strain of whites becomes effected, it 

 is easily rebuilt by a cross with a colored mouse, preferably 

 a black. The first young will no doubt be blacks, but if 

 these brothers and sisters are bred together, one white in 



