THE DETERMINATION OF DOMINANCE. 



299 



Ratios of these adult types 71 : 

 Expected 63.75 



132 : 

 127.50 



62 : 

 63-75 



Four experiments of this type have been carried through to the 

 fourth and fifth generations with perfectly uniform results thus 

 far. 



L. undecimlineata ^ X & L. signaticolUs . 

 Exp. No. H 701. 

 A virgin female of L. undecimlineata, from Exp. No. 722, g. 

 IV (E), was crossed with a male L. signaticolUs, from Exp. No. 

 419, g. XIII (CAAB) under the following conditions: 



Food : Normal — uniform. 



T. R. H. 



Max. 105° F. Max. 85 per cent. 



Min. 80° F. Min. 70 per cent. 



Av. 92° F. Av. 79 per cent. 



The larvae of the F^ generation were in the first stage identical ; 

 in the second stage they were clearly divisible into sharply marked 

 classes of white and yellow in the proportion of wh. 30: yl. 26. 

 The yellow larvae in the third stage divided into YIS 1 1 and Yls 9, 

 and the white larvae gave three groups: pure pearly white like 

 the female parent, whs i ; larvae which were yellowish white 

 without spots, whys 14; and larvae which were yellowish white' 

 with spots, whyS 10. The dorsal spots of the larvae in the third 

 stage were in this case variable. The single pearly white larva 

 gave rise to a female exactly like the parent type and four classes 

 of larvae: white without spots (Whs), white with spots (WhS), 

 yellow without spots (YIS), and yellow with spots (Yls). Each 

 gave rise to a group of highly variable mid types, in which the 

 range of variation was from the condition of the female parent 

 to that of the male parent. Fourteen pairs of these were tested 

 out in the F2 generation and they were all found to be uniformly 



