292 MK. C. C. HURST : EXPERIMENTAL STUDIES 



From the above results it would appear that the unit characters, 

 short and Angora coat, in their heredity follow the Mendelian 

 type Pisum as regards dominance, segregation, and gametic 

 purity. 



(2) ISTOEMALITY AND AlBINISM. 



The normal Belgian rabbit has a pigmented skin, coloured 

 coat, dark eyes, and normal demeanour, while the albino Angora 

 has a clear skin devoid of pigment, white coat, pink eyes, and a 

 curious habit of swaying the head from side to side whenever the 

 body is at rest. So far as these experiments go, all these 

 apparently different characters of the albino are correlated and 

 inherited as a single character or unit, which may be simply 

 called albinism as opposed to normality. 



In describing these experiments, therefore, it will be under- 

 stood that the term normal includes a pigaiented skin, coloured 

 coat, dark eyes, and normal demeanour, while the term albino 

 comprises a clear skin, white coat, pink eyes, and the swaying 

 habit. As already noted, both the normal Belgians and the 

 albino Angoras breed true when mated with their own kind. 



(a) Mrsi Generation (FJ. 



No. 1 normal doe mated with No. 2 albino buck produced 26 

 normal hybrids. The reverse cross, No. 3 albino doe mated with 

 No. 4 normal buck, produced 16 normal hybrids. The 26 normal 

 hybrids of the first cross did not show the slightest trace of the 

 albino parentage in any respect. The 16 normal hybrids of the 

 reverse cross (with one exception) had a few white markings on 

 the fore extremities, but, as will be seen later, these do not seem 

 to be connected with simple albinism at all, but rather with the 

 Dutch markings latent in the albino (see under Sect. 4, p. 314). 

 In Mendelian terms, therefore, normality may be said to be 

 dominant over albinism, which is recessive. 



Further experiments recently carried out show that the normal 

 character of other races as well as the Belgian is similarly 

 dominant over albinism. Altogether 94 hybrids have been raised 

 by crossing normal and albino individuals and all have proved 

 to be normal hybrids, whether the albino was used as the male 

 or the female parent. It appears that in these cases also the 

 phenomenon of dominance is peculiar to the character itself, 

 and is not influenced by change of sex, iudividuals, or race. The 



