Experiments with other Mammals 107 



known remained practically unexplained. By the aid of the 

 MendeHan principles we are able to see at once that there are at 

 least four pairs of distinct characters concerned in the offspring 

 of the second generation, each pair being inherited independently 

 of the other; namely, short hair versus longhair, pigmented coat 

 versus albino, gray versus black coat, uniform versus marked 

 coat.^ Hurst takes up these four pairs of contrasting characters 

 and deals with them separately. 



Short Hair versus Long Hair. — The short hair of the Belgian 

 breed rarely exceeds one inch, while the long hair of the Angora 

 breed may exceed six inches. The first hybrids had short hair, 

 the influence of the Angora not being apparent. A careful ex- 

 amination, however, revealed what appeared to be faint traces 

 of the Angora influence in both length and texture. The hairs 

 of the hybrid coat were slightly longer, seemed softer to the touch, 

 and were apparently more densely distributed than in the pure 

 short coat. These traces of Angora influence are shght and 

 might easily be overlooked. 



When these short-coated hybrids {F-^ were inbred, there were 

 produced 171 young, of which 70 reached the age of two months 

 or more, when the character of the hair becomes manifest. Of 

 these 53 were short- and 17 long-haired. This is a close ap- 

 proximation to the MendeHan expectation of 51 to 17. The 

 short hair was Hke that of the grandparent, the long hair Hkc 

 that of the other grandparent. When the long-haired Angoras 

 were bred together they produced in the next generation only 

 Angoras. The short-coated individuals mated together gave 

 both short-haired, and Angoras in MendeHan proportions. 



Pigmented Coat versus Albino, — The cross gave in one case 

 26 totally pigmented individuals ; in another case the fore-feet 

 showed some white markings, which Hurst thinks is not due 

 to the albino influence, but to Dutch marking latent in the 

 albinos. The hybrids, when inbred, produced 132 pigmented 

 and 39 albinos, the MendeHan expectation being 129 : 43. 



^ In the marked coat there is white on the ends of the feet and the tip of the 

 nose. The Dutch is an extreme form of this marking. 



