COAT CHARACTERS IN GUINEA-PIGS AND RABBITS. 



EXPERIMENTS WITH RABBITS. 



Certain experiments with rabbits, while less extensive than those 

 made with guinea-pigs, serve to confirm and extend some of the con- 

 clusions already reached. 



CROSS BETWEEN TWO DIFFERENT TYPES OF ALBINOS. 



Particularly instructive are the experiments with two different types 

 of albinos, the pure or wholly unpigmented type, and the Himalayan 

 or peripherally pigmented type. 



A pair of Himalayans purchased of a dealer produced in two succes- 

 sive litters only good Himalayan young, 12 in number. Presumably, 

 therefore, they were pure. 



A pure white female rabbit born of pigmented parents, but herself 

 wholly unpigmented, was likewise found to breed true when mated to 

 animals like herself. Crosses were now made between the two breeds, 

 as follows : 



All the young had pigmented extremities ; some were nearly or quite 

 as heavily pigmented as those of the Himalayan parent, but others had 

 pigmentation less heavy than that of the Himalayan parent ; these we 

 may call intermediate. Still others bore pigment on part only of the 

 areas which are pigmented in a pure Himalayan ; thus the foot might 

 be pigmented, but its toes pure white, or the center of the nose white, 

 with a sooty band lying above and to either side of it. Individuals such 

 as this we may call mosaics. Dominance of the peripheral pigmentation 

 was, accordingly, very imperfectly realized in the hybrid offspring. 

 Nevertheless, segregation of the two types of albino character involved 

 in this cross takes place with great regularity when the hybrids form 

 gametes, and this is true alike of all three sorts of young, the dark 

 Himalayan, the intermediate, and the mosaic, as the following matings 

 show. 



