CONTENTS. 



Introduction, . .... .... 5 



Experiments with guinea-pigs, ..... ... 6 



HereditA' of coat color, ........... 6 



Coat of the wild cavy, ...... 6 



Color varieties of the domesticated cavy or guinea-pig, .... 7 



Agouti, . . . . 7 



Yellow, . . .... .7 



Chocolate. .... ... . . 7 



Black, . . . ... 8 



Albino, . ... 8 



Spotted, . . . . . 12 



Brindled, .... 13 



Roan, and Silvered, ..... . '4 



Results of crossing the elementary color varieties, . . , 14 



Albinos and pigmented animals, ... ... 14 



Albinism and the "Law of ancestral heredjty," . 16 



Albinism and sexual prepotency, . . ...... 23 



Albinism and latent pigment characters, . . . -4 

 Intercrossing of different pigment types, . . . .26 



The agouti type, .... .... 26 



Agouti X agouti, . . 26 



Agouti x black, . . ..... 26 



Agouti x red, . . 28 



Agouti x albino, . .... 28 



The black type, ... ..... 31 



Black x red, . . . . ... 31 



Black x albino, . . .... . . 34 



The red type, . . ... 36 



Red x albino, . . ........ 37 



Black-eyed white, . . . . 37 



Comparison with pink-eyed mice, ... . . 47 



Heredity of rough coat, . . . ... 56 



Prepotency and dominance, --... 58 



Heredity of long coat, ... . . .... 64 



Correlation among coat characters, . ..... 67 



Experiments with rabbits, . . ... . . 70 



Cross between tsvo different types of albinos, ...... 70 



Heredity of long or Angora coat, .... 73 



Heredity of lop-ears, ...... .... 74 



Summary, . .... 75 



Bibliography, . ...... 77 



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