E. J. Allen and E. W. Sexton 363 



2. Tested Albinos mated with tested Albinos. 



Unfortunately a large number of the tested Albinos died before 

 they could be used in this section. The results of the survivors are 

 as follows : — The unspotted pairs — 



Expt. III6. </* 9 X $ 3, both carrying Black and Red ; 155 unspotted 

 young and 118 spotted ; 43*2 °/^ spotted, or 9 : 7 ratio. 



Expt. X 6. (^1 and $ 10, both carrying Red; 7 unspotted and 11 

 spotted. 



Expt. Xc. The same male, which had now developed spots, and $ 64; 

 28 unspotted and 57 spotted ; 67 °/^ spotted. 



Expt. XI 6. t/* 11 and $ 65, one carrying Red and one Black and Red; 

 7 unspotted and 5 spotted. 



Expt.XII6. j/'12 and $ 78, both carrying Black and Red; 13 un- 

 spotted and 17 spotted. 



Two pairs of unspotted Fi young from Expt. Xc were mated; one 

 pair gave 26 unspotted and 68 spotted; the otber pair 12 unspotted 

 and 20 spotted. 



$ 65 from XI 6 was also put with c/'82, a spotted Albino carrying 

 Black, and gave 21 unspotted and 15 spotted. 



The spotted pairs. Of the spotted F^ young of Expt. Ill 6 one male 

 was mated with three females ; from the first there were 41 unspotted 

 and 53 spotted young; from the second 17 unspotted and 42 spotted; 

 and from the third 8 unspotted and 51 spotted. 



Expt. 1166. (From Family I.E., see pp.348 and 354.) Male and female 

 both carrying Red; 17 unspotted, 30 spotted. 



Expt. 93c?. (From I.E.) Male and female both carrying Red ; 16 un- 

 spotted, 17 spotted. 



Two other experiments may be quoted : a male carrying Red was 

 mated with two females from different broods of Family C. 176 (these 

 were not tested for colour) ; one gave 31 unspotted young and 30 spotted; 

 the other 33 unspotted and 32 spotted. 



Summary. When Albinos were mated with Pure Reds from a strain 

 which only very occasionally threw spotted animals, the percentage of 

 spotted in a family varied from 1 or 2°/^ to 187o> ^ result which does 

 not differ from that obtained when coloured animals from a spotted 

 strain were mated together (cf p. 357). 



The percentage of spotted did not seem to be influenced by the 

 colour factor carried by the Albino parent, and there is no obvious 



