310 ME. C. C. HUllST : EXPERIMENTAL STUDIES 



The above results point to the following conclusions : — 



(1) That both pure-bred and extracted albinos carry in their 

 gametes certain colour-factors. 



(2) Some albinos give off gametes containing the black factor 

 only, while others give off gametes containing black and gametes 

 containing grey, on the average in equal numbers. 



(3) These colour-factors remain latent when albinos are mated 

 together, but become patent when the albinos are mated with 

 normal individuals. 



(4) These lament colour-factors appear to follow the ordinary 

 Mendeliau rules of segregation and gametic purity. 



(5) That the black character, which appeared in the second 

 generation of the hybrids betvveen the yellow-grey Belgian and 

 the white Angora, was introduced by the albino Angora. 



These conclusions, arrived at from experiments with Eabbits, 

 fully confirm those already obtained 'by Prof. Cuenot in his 

 important experiments with Mice ; and although of necessity my 

 experiments have been carried out on somewhat different lines, 

 yet the conclusions are the same in principle, and in presenting 

 them I wish to acknowledge my indebtedness to Prof. Cuenot 

 and Mr. Bateson for their useful suggestions. There is no doubt 

 that the demonstration of the fact of latent colour-factors 

 being carried by albinos is of great significance, and will help to 

 throw light upon a large number of observations, contributed 

 by many observers in both animals and plants, that hitherto have 

 remained obscure. 



The Disappearance of the Yellotv-grey Character. 

 With regard to the disappearance of the original yellow-grey 

 character of the Belgian in all the generations, a number of 

 experiments are now in progress, which, it is hoped, will throw 

 some light upon the matter, as soon as completed*. 



(4) TJ]!fIEOEM AND MaRKED CoAT. 



In the original experiments the Belgian parents had a uniform 

 or self-coloured coat, with no trace of white markings on the 

 extremities. (The almost^ white ventral area may for this pur- 

 pose be disregarded.) 



This self-colour character breeds true, so far as my experiments 



* So far it is not possible to suggest what is the meaning of the non 

 appearance of the Belgian coat-colour in Fg and F3. 



