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THE AMERICAN NATURALIST [Vol. XLYI 



The other ease studied by Galton, the inheritance of the tri- 

 color condition in Bassett hounds, no one up to the present time 

 has attempted to explain on any ground other than that taken 

 by Galton in his law of ancestral heredity, although it is now 

 generally conceded that his law does not apply to color in- 

 heritance in general. 



The tricolor condition seen in dogs is found in very few other 

 animals, one of which however is the guinea-pig, the tricolor 

 variety of which I have had an opportunity to study for some 

 years. The observations made on tricolor guinea-pigs throw 

 light on the facts observed by Galton regarding tricolor dogs. 

 They show wherein Galton 's interpretation fails and what ad- 

 vantages a Mendelian interpretation has as applied to this case. 



The tricolor condition of guinea-pigs is one of long standing. 

 Cuvier reports it as depicted by Aldrovandus, who made the 

 first scientific description of the guinea-pig, soon after 1550. 

 This color variety had probably been in existence for a long 

 time before the discovery of America. The natives of Peru still 

 rear it for food in the recesses of their adobe cabins, as their 

 ancestors have doubtless done for untold centuries. Neverthe- 

 less it does not breed true, and can not be made to do so. 



The tricolor animal is white marked with irregular but distinct 

 blotches of black and yellow. Tricolors produce besides tri- 

 colors young which are black-and-white or yellow-and-white, but 

 never in my experience those which are wholly free from white. 

 In other words they breed true to spotting with white, but not to 

 spotting with black and yellow. The black-and-white as well as 

 the yellow-and-white offspring of tricolor parents may produce 

 tricolor young. Indeed any one of these three conditions is able 

 to produce both the others. See Table. Notwithstanding the 



