ON HKRBDITY IN^ IIABBITS. 307 



pigment. 2 of these young were tested with pure blacks and 

 have so far given the following results : — 



No. 23 albino doe mated with a pure black gave 5 blacks aud 

 1 grey. No. 24 albino buck mated with a pure black gave 

 3 blacks : mated with a grey hybrid containing recessive black 

 gave 6 blacks aud 1 grey. 



Although these results are few in number, yet it seems certain 

 that No. 23 albino is carrying both grey and black, while No. 24 

 is apparently carrying black only. 



The Mendelian expectation for albino (gr.-bl.) x albino (bl.) 

 is 1 albino (gr.-bl.) and 1 albino (bl.), which is apparently the 

 result. The fact that in this case father aud son are apparently 

 carrying black only, while mother and daughter are apparently 

 carrying grey and black, may be but a coincidence. 



All the above results with pure-bred albinos are in accordance 

 with the conception that albinos give off gametes carrying certain 

 colour-factors which remain latent until the albino is crossed 

 with a pigmented individual, and yet, during their latency, obey 

 the Mendelian laws of segregation and gametic purity. Further 

 support is given to this conception by the results of the 

 following experiments with extracted albinos. 



Colour-factors latent in Extracted Albinos. 



7 extracted albinos were tested for latent colour-factors, and 

 of these, 2 apparently carried black only, while 5 apparently 

 carried both grey and black. No. 14 albino buck mated with 2 

 pure blacks gave 6 blacks : mated with 2 grey hybrids containing 

 recessive black it gave 3 greys and 5 blacks. 



No. 45 albino doe mated with two pure blacks gave 9 blacks. 

 These two albinos, which were apparently carrying blaclc only, 

 were extracted from No. 5 grey hybrid containing black, mated 

 with No. 2 albino apparently carrying black, and are interesting 

 as showing that albinos apparently carrying black only can be 

 extracted from greys provided that the latter also contain black. 

 No. 15 albino doe mated with 2 pure blacks gave 5 greys aud 7 

 blacks ; this albino was extracted out of No. S grey (bl.) X No. 2 

 albino (bl.). 



No. 16 albino doe mated with a pure black gave 7 greys and 

 5 blacks; this albino was extracted out of No. 7 pure grey x 

 No. 2 albino (bl.). 



21* 



