Mlscellaiiea 103 



(c) Miüc wliich are all gray cxcept ou the l)clly anil t.ail wliicli are always nearly white. 

 At a casual glaiice thi.s typo niight easily bo mistaken for a h<iii8c mou.se ; Ijut inspection cjf its 

 belly reveals its hybrid nature. Fig. 4. 



(d) Mice which are all fawn coloiired e.xoopt nn the belly. Tlio colour is like tliat nf the 

 marking.s oii the Japanese waltzers : its distribution corresponds to that of the gray in (c). 



a and b merge into one anothor, and the Standard of Separation is niurc or less arliitrary ; 

 but the line dividing b or a froni c is at pre.sciit quite .sharp. 



The follciwing is a record of the crosscs : 



C'ro&i 1. 9 cross-bred albino. 



It will be Seen by reference to the above figures that there are 18«, 13 6, 15 c; and 2(1, that is 

 to say, 31 cases at Icast out of 48 in which albinism is not recessive ; and even in c, which is 

 a gray mouse superficially not unlike the house mouse, we by no raeans find a coinplete disap- 

 pearance of whiteness ; for as it has already been said, their bellies are nearly white ; which is 

 not true of the house mouse : and the bellies of d are like those of c. 



