70 



THE INHERITANCE OF COLOR IN MICE. 



Black x pink-eyed brown. 



Cross 74. Black heterozygous in dark eye crossed with homozygous pink-eyed brown. 

 Y 2 Br 2 B 2 D 2 Pp x Y 2 Br 2 D 2 p 2 . Expectation, IB, 1 pB. 



Cross 75. Black heterozygous in dark eye and black crossed with homozygous pink-eyed 

 brown. Y 2 Br 2 BD 2 Pp x Y 2 Br 2 D 2 p 2 . Expectation, 1B,1 pB, 1 Br, 1 pBr. 



Black x pink-eyed dilute brown. 

 Cross 75a. Both parents homozygous. Y 2 Br 2 B 2 D 2 P 2 x Y 2 Br 2 d 2 p 2 . Expectation, all B. 



Cross 75b. Black heterozygous in dark eye, crossed with homozygous pink-eyed dilute 

 brown. Y 2 Br 2 B 2 D 2 Pp x Y 2 Br 2 d 2 p 2 . Expectation, 1 B, 1 pB. 



X. Dilute Black, YBrBdP (Fig. 10). 



Eyes black; ears, tail, and feet moderately pigmented. Ventral hairs slate-colored. Dorsal 

 hairs are deep blue slate, somewhat washed-out, and at times resembling a very deep- 

 colored dilute black agouti. There is a small tuft of light hairs at the base of the ears. 

 Light yellowish hairs scattered on sides and feet, and around the anus. Unlike the 

 pink-eyed black form next to be described, one would not hesitate in calling the dilute 

 black animal, black pigmented. 



Dilute black x dilute black. 

 Cross 76. Both parents homozygous. Y 2 Br 2 B 2 d 2 P 2 x Y 2 Br 2 B 2 d>P 2 . Expectation, all dB. 



