100 Experimental Zoology 
314 young, all pigmented ; and these last give in later generations 
some albinos. The results agree fairly closely with Mendelian 
expectations. 
Castle has found, as had Allen and Cuénot for mice, that 
albinos, although breeding true, may carry latent or suppressed 
Fic. 7. Upper figure, short-haired, smooth coat red guinea pig. Lower figure, 
long-haired, rough coat albino. (After Castle.) 
colored characters. Thus one albino individual, a male, when 
mated with red females produced offspring marked with black. 
Another albino crossed with the same and with other red females 
gave young marked with black and red in about half the cases, 
the other half showing only red or yellow, but no black. A third 
albino mated with red females produces only red or yellow 
offspring, never black ones. In the light of these results, Castle 
