56 



THE INHERITANCE OF COLOR IN MICE. 



Black agouti x pink-eyed brown. 



Ckoss 21. Black agouti heterozygous in dark eye and agouti, crossed with homozygous pink- 

 eyed brown. Y 2 Br 2 B 2 D>PpA x Y 2 Br 2 D 2 p 2 . Expectation, 1 BAg, 1 pBAg, 1 B, 1 pB. 



Black agouti x pink-eyed dilute brown. 



Cross 21a. Homozygous black agouti crossed with homozygous pink-eyed dilute brown. 

 Y 2 Br 2 B 2 D 2 P 2 A 2 x Y 2 Br 2 d 2 p 2 . Expectation, all BAg. 



Cross 21b. Black agouti heterozygous in black, density, and agouti crossed with homozy- 

 gous pink-eyed dilute brown. Y 2 Br 2 BDdP 2 A x Y 2 Br 2 d 2 p 2 . Expectation, 1 BAg, 

 1 BrAg, 1 B, 1 dBAg, 1 dBrAg, 1 Br, 1 dB, 1 dBr. 



II. Dilute Black Agouti, YBrBdPA (Fig. 2). 



Eyes black, ears moderately pigmented, ventral hairs light slate colored with a yellowish 

 tinge. Tail moderately pigmented. Dorsal hairs showing the "agouti" pattern dis- 

 tinctly but somewhat faded, or washed out in appearance. Tuft of light hairs present 

 at base of the ears and around the anus. 



Dilute black agouti x dilute black agouti. 

 Cross 22. Both parents homozygous. Y 2 Br 2 B 2 d 2 P 2 A 2 . Expectation, all dBAg. 



Cross 22a. Both parents heterozygous in black, dark eye, and agouti. Y 2 Br 2 Bd 2 PpA. 

 Expectation, 27 dBAg, 9 dB, 9 pdBAg, 9 dBrAg, 3 dBr, 3 pdB, 3 pdBrAg, 1 pdBr. 



