302 ME. C. C. HTJEST : EXPEEIMENTAL STUDIES 



greys. 7 greys of tHe first generation were tested together, and 

 of these 6 proved to be hybrids, giving both grey and black 

 young, usually in the same litter : the remaining one has so far 

 given no blacks, and presumably is a pure grey. 



The pure grey doe (No. 7) mated with 2 hybrid greys con- 

 taining latent black (Nos. 10 and 12) produced 22 grey young. 



The 6 hybrid greys mated together produced 110 coloured 

 young, of which 85 were greys and 25 were blacks. 



The individual results were as follows : — No. 5 gave 8 grey& 

 and 5 blacks ; No. 8, 22 G- and 6 B ; No. 9, 33 G- and 10 B ; 

 No. 10, 59 G- and 19 B ; No. 11, 22 GT and 4 B ; and No. 12, 

 26 G- and 6 B. 



All the 7 individuals gave white as well as coloured offspring ; 

 but these have already been dealt with under albinism (Sect. 2» 

 p. 294). 



The following table gives the individual matings, with the 

 numbers of greys and blacks in each litter : — 



Table 20. 



Hybrid Greys bred together (F,). 



Matings. Grey. Black. 



H 5 X H 12 4 2 



H5XH10 4 3 



H8 XHIO 5 3 



HSxHlG 8 



H8 xHlO 6 2 



H8 xHlO 3 1 



H 9 X H 10 5 3 



H9XH10 5 



HOxHlO 5 1 



H9xH10 7 



H9xH10 2 5 



H9xH10 3 1 



H9XH12 6 



Hll X H12 5 1 



H11XH12 6 1 



H 11 X H 12 5 2 



H 11 X H 10 6 



Total 85 25 



The greys of the second generation had wild-grey coats like 

 their parents, a tew individuals appeared to have rather more 



