EXTENDED SERIES. 



77 



Cross 98a. Dilute brown heterozygous in dark eye, crossed with pink-eyed brown heterozy- 

 gous in density. Y^Br-APp X YJBrJDdpi. Expectation, 1 Br, 1 dBr, 1 pBr, 1 pdBr. 



XV. Pink-Eyhd Bhown, YBrDp (Fig. 15). 

 Eyes clear pink. Ears, tail, and feet unpigmented. Hairs on ventral surface dull yellowish 

 throughout their length. The yellow hairs at the base of the ears and around the anus 

 are very similar to the rest of the coat, but are, nevertheless, distinguishable from it. 

 The dorsal hairs are rich fawn colored, lighter than the coat of the pink-eyed brown 

 agouti. 



Pink-eyed brown x pink-eyed brown. 



Cross 99. One or both of the parents homozygous. YiBriDipz x Y2Br2D2p2. Expectation, 

 only pBr. 



Pink-eyed brown x albino. 

 (Test matings to determine the gametic constitution of the albinos.) 

 Cboss 100. Pink-eyed brown heterozygous in the color factor crossed with an albino, poten- 

 tially a homozygous brown agouti. YBriDspi xBriDiPiAi. Expectation, 1 BrAj, 1 Tf 



Cross 101. Pink-eyed brown heterozygous in the color factor, crossed with an albino, poten- 

 tially a homozygous brown. YBr^Dipi x BriD^Pi. Expectation, 1 Br, 1 W. 



XVI. Pink-eyed Dilute Brown, YBrdp (Fig. 16). 



Eyes clear pink. Very pale pigmentation throughout hairs and skin, a close approximation 

 to a dirty brownish cream but still preserving the streaky washed-out appearance 

 clearly. This form is as characteristic and easily distinguished as the pink-eyed dilute 

 black. The ear tufts are indistinguishable from the rest of the coat. Pink-eyed dilute 

 browns crossed inter se have given 120 recorded young, all pink-eyed dilute brown. 



It must be remembered that all these descriptions of color varieties are intended to be merely 

 as they appear to the unaided eye. Many of the regions here spoken of as pink or 

 unpigmented have, upon microscopic examination, yielded a small amount of pigment. 



