May 19, 1911] 



SCIENCE 



785 



In 1907 a Bagdad White female was mated 

 with a Bagdad White male from 9:30 a.m. to 

 10:65 A.M. and then with a French Yellow 

 male from 10 :55 a.m. to 12 :15 p.m. From this 

 mating there were produced (1908) 25 white 

 cocoons and 13 yellow cocoons. Mating 

 (1908) two of these white cocooners together 

 produced (1909) a small lot divided equally 

 between white cocoons and yellow cocoons 

 (sick lot). Mating (1909) two of these white 

 cocooners together produced (1910) a small 

 lot of white cocooners containing one yellow 

 cocoon (straggler?). (Wherever my records 

 show a single yellow in an otherwise white lot 

 or a single white in an otherwise yellow lot I 

 prefer " straggling " to any other explana- 

 tion!) A mating (1909) of two yellow co- 

 cooners produced (1910) a small yellow lot 

 containing one white cocoon. A mating 



(1908) of a white and a yellow from the 25 

 white, 13 yellow lot produced (1909) a small 

 lot composed equally of white and of yellow 

 cocooners. Mating (1909) two of these white 

 cocooners together produced (1910) 23 white 

 cocoons and 2 yellow cocoons. 



In 1907 another Bagdad White female was 

 mated with a Bagdad White male from 

 9:30 A.M. to 10:55 a.m. and then with a 

 French Yellow male from 10:55 a.m. to 

 12 :15 P.M. From this mating there were pro- 

 duced (1908) 33 white cocoons and 19 yellow 

 cocoons. Mating (1908) two of the yellows 

 produced (1909) a small lot equally divided 

 between yellow and white cocoons. Mating 



(1909) two of these white cocooners produced 



(1910) 9 white cocoons and one yellow. 

 Mating (1908) a yellow and a white from the 

 haK yellow, haK white Fj generation produced 

 (1909) 22 white cocoons. And mating (1909) 

 two of these together produced (1910) a small 

 lot of all white cocooners. Mating (1908) 

 another yellow with another white from the 

 Fj generation produced (1909) 6 white co- 

 coons and 10 yellow cocoons. Mating (1909) 

 two of these yellow cocooners produced (1910) 

 a small lot equally divided between yellow 

 and white cocoons. Mating (1908) two white 

 from the F^ generation produced (1909) a 



small lot all white except for a single yellow 

 cocoon. And mating (1909) two of these 

 whites together produced (1910) an aU white 

 lot of cocoons. 



In 1907 a French yellow female was mated 

 with a French yellow male from 9:15 a.m. to 

 10 :45 P.M. and then with a Bagdad white male 

 from 10:45 a.m. to 12:15 p.m. From this 

 mating there were produced 57 white cocoons 

 and 74 yellow cocoons. Mating (1908) two 

 yellows of this F^ generation produced (1909) 

 22 yellow and 8 white cocoons. Another simi- 

 lar mating (1908) produced (1909) 23 yellow 

 and 2 white cocoons. And still another pro- 

 duced 14 yellow and 5 white cocoons. Mating 

 (1908) a yellow and a white of the F, genera- 

 tions produced (1909) 17 yellow and 19 white 

 cocoons. Another similar mating (1908) pro- 

 duced (1909) 21 yellow and 17 white cocoons. 

 Mating (1909) two whites of the F, generation 

 produced by two yellow parents produced 

 (1910) an all white lot. Mating (1909) two 

 more whites of this F^ lot produced (1910) 

 another all white Fj lot. Mating (1909) two 

 yellows from this same F, lot produced (1910) 

 an all yellow lot. Mating (1909) another pair 

 of these F„ yellows produced (1910) 20 yellow 

 and 9 white cocoons. Mating (1909) two 

 whites of the F, generation produced by a 

 white X yellow produced (1910) 25 whites, 11 

 yellows and a double cocoon spun together by 

 a white cocooning larva and a yellow cocoon- 

 ing larva. Another mating (1909) of two 

 whites from this same F^ lot produced (1910) 

 19 white cocoons and 6 yellow cocoons. 



In 1907 a French Yellow female was mated 

 with a Bagdad White male from 9:40 a.m to 

 11:10 A.M. and then with a French Yellow 

 male from 11:10 A.M. on to the death of the 

 moths. This mating produced (1908) 14 

 white cocoons and 140 yellow cocoons. Mating 



(1908) two of the white cocooners produced 



(1909) 30 white cocoons and 10 yellow co- 

 coons. Mating (1909) two of these F, genera- 

 tion white cocooners produced (1910) 62 white 

 cocoons and no yellows. Mating (1908) two 

 more of the Fj generation white cocooners 

 produced (1909) 20 white cocoons and 10 yel- 

 low cocoons. Mating (1909) two of the F^ 



