EXTENDED SERIES. 



67 



IX. Black, YBiBDP (Fig. 9). 



Hairs on ventral surface not so heavily pigmented as the dorsal hairs, and of a dull slaty 

 black. Tail dark. Dorsal hairs deep, glossy black. Tuft of yellowish hairs at base of 

 ears. A few yellowish hairs scattered along the flanks, sides and feet. The hairs 

 around the anus are light yellowish. The feet are dark. 



Black X black. 



Cross 62. One or both of the parents homozygous. YiBi-iBiD-iPi x YiBr-iB-iDiP'i. Expec- 

 tation, all B. 



Cross 63. Both parents heterozygous in black. YoBviBDiPy x YiBriBDiPo. Expecta- 

 tion, W, 1 Br. 



Mating. 



Parents. 



B. Br. 



1x400.. 6 2 



Cross 64. Both parents heterozygous in density. YiBr^BiDdPi x YiBr-iB-iDdP^. Expec- 

 tation, 3 B, 1 dB. 



Cross 65. Both parents heterozygous in dark eye. YoBr^BiDiPp x YiBriB^DoPp. Expec- 

 tation, 3 B, 1 pB. 



Mating. 



492 

 168 

 189 

 114 

 131 

 135 

 379 



Parents. 



Unmarked X 2948 



455x919 



4.50x540 



Unmarked X 454 



543x444 



450x444 



Unmarked x unmarked . . 



