go BREEDING 



The albino waltzer (No. 4) possesses the recessive 

 character, waltzing, of one parent, and the recessive 

 character, albinism, of the other parent, and as both 

 these characters breed true when they reappear in 

 the second hybrid generation, the new albino waltzer 

 will be a constant variety from the first. The colour- 

 ing of the pure waltzer and the normal progression 

 of the albino are combined in mouse No. 12. Mice 

 in which the waltzing character is associated with 

 one of the colours or arrangements of colour not 

 existing in either of the two parents of the cross 

 constitute a further set of new forms. The most 

 beautiful of these is undoubtedly the lilac waltzer 

 (a specimen of which I have not figured), and the 

 most curious of them is the form shown at No. 6, a 

 mouse in which the coloration of the first hybrid 

 generation is associated with the waltzing character 

 — a house-mouse that cannot run away. Whether it 

 was a constant variety or not would depend upon 

 whether, when mated with its like, it bred true to 

 its colour or not; for it would be certain to breed 

 true to the waltzing character if mated with a 

 mouse like it. But as the majority of the mice in 

 Group B produce, again, representatives of Groups A, 

 B and C, it is impossible that a constant race of mice 

 like No. 6 could be raised, except after long waiting 

 for two mice, of opposite sexes, both of which breed 

 true to grey coat and black eye. 



In this chapter I have set forth an example of 

 reversion on crossing, and the result of breeding from 

 these reversionary hybrids. The inheritance of colour 



