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. 

 YiBriBiD^Pp X YiBrzDip^. Expectation, 1B,1 pB. 



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

 brown. Y^BriBDiPp x YiBnDiPi. Expectation, 1 B, 1 pB, 1 Br, 1 pBr. 



Black X pink-eyed dilute brown. 

 Cross 75a. Both parents homozygous. YiBr^BiD^Pz x YiBrod^p^. Expectation, all B. 



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

 brown. YiBriBtDiPp x YiBr2diP2. Expectation, 1 5, 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 ba.se 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. Y2Br2B2d>P2 x Y2Br>B2d2P2. Expectation, all dB. 



