Dichromatism in Lina Lapponica. 



123 



obtains for the total number of offspring of each pair, as well as 

 for the sum total in both series. 



Dissimilar parents produced on the whole mixed broods with 

 preponderance of individuals in the S color type. Records of 

 individual broods show that that preponderance was maintained 

 in every S c? X B 9 cross but four, namely, in 12 out of 16 



Table II— B X B. {See also Table VII.) 



crosses, and in every S 9 X B c? cross but two, namely, in 12 

 out of 14 crosses. 



Experiment 2. My next effort was to see if I could by selection 

 bring the two differentiating characters to breed true in certain 

 lineages. I, therefore, selected ten broods from among the pure 

 broods (broods true to parents) produced by B X B and ten broods 

 from among the pure broods produced by S X S. All the males 

 of one brood were placed in a breeding jar with all the females of 



