44 MAMMALS 



every four youngsters may be expected. These are known 

 as extracted whites, and if mated with whites, will never 

 produce any other color. 



Of the colored mice, blacks are probably the best known. 

 The color should be sound and dense throughout, and free 

 from rustiness. Light feet and tails are the most common 

 faults. 



Blues are merely diluted blacks, of a dark slate color. 

 They should be free from brown shades, and in feet and 

 tails are subject to the same weakness as the blacks. These 

 two colors are commonly bred together, but once the strains 

 are firmly established, much better results, particularly with 

 blues, can be obtained by keeping the colors pure. 



Yellow mice have been known variously as fawn, cinna- 

 mon and orange, and of late have come to be described as 

 red. This seems decidedly misleading, as the color of these 

 mice is not at all the shade known as red in other animals, 

 markedly in cavies. 



No matter what the name, the color certainly is one of 

 the most attractive found in mice. When seen at its best, 

 the red mouse is of a bright, rich orange-yellow, a shade 

 not easy to secure. Chocolates are most frequently used in 

 crossing with reds, the interchange of blood seeming to bene- 

 fit both varieties. 



It is a curious fact that while all mice of advanced age 

 tend to become fat, reds seem more inclined than other 

 colors to take on flesh. The writer recently saw two red 

 does of such an unbelievable size that he could hardly be- 

 lieve they were mice at all. Careful dieting is necessary 

 to keep good specimens of this color in presentable con- 

 dition. 



Chocolates should be of the dark color the name implies. 

 Much crossing with reds leads to the production of a lighter 

 shade, and recourse to black blood is necessary. Once the 



