786 



SCIENCE 



[N. S. Vol. XXXIII. No. 855 



generation white cocooners produced (1910) 

 a small sick lot, partly white and partly yel- 

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

 yellow cocooners produced (1910) a small 

 weak lot of 12 yellow cocoons and 2 white co- 

 coons. Mating (1908) two of the Fj genera- 

 tion yellow cocooners produced (1909) 18 

 yellow cocoons and 2 white cocoons. Mating 



(1909) two of the F, yellow cocooners produced 

 4 yellow cocoons and one white cocoon. 

 Mating (1908) two more of the F, generation 

 yellow cocooners produced (1909) 59 yellow 

 cocoons and no white cocoons. Mating (1909) 

 two of these F^ yellow cocooners produced 



(1910) 47 yellow cocoons and no white co- 

 coons. Mating (1908) a yellow coeooner and 

 a white coeooner of the same Fj generation lot 

 produced (1909) 18 white cocoons and 14 yel- 

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

 white cocooners together produced (1910) 29 

 white cocoons and 11 yellow cocoons. Mating 



(1909) two of the yellow cocooners of the F^ 

 lot produced (1910) a sick lot of 3 white co- 

 coons and 1 yellow cocoon. Mating (1908) 

 another yellow and white pair of the same F^ 

 lot produced (1909) 10 white cocoons and 10 

 yellow cocoons. Mating (1909) two of these 

 white cocooners produced (1910) 93 white co- 

 coons and 25 yellow cocoons. Mating (1909) 

 two of the F, yellow cocooners produced 



(1910) 8 white cocoons and 35 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. to 12.25 p.m. This 

 mating produced 56 salmon (i. e., pinkish yel- 

 low) cocoons and 34 salmon to golden yellow 

 cocoons. (All of these in the general category 

 yellow but varying in shade from pinkish yel- 

 low to deep old gold yellow). Mating (1908) 

 two salmon cocooners produced (1910) 13 

 salmon cocoons and 3 white cocoons. Mating 

 (1909) two of these F, salmon cocooners pro- 

 duced (1910) all salmon lot. Mating (1908) 

 another salmon Fj pair produced (1909) 17 

 salmon cocoons and 8 white cocoons. Mating 

 (1909) two of these F, salmon cocooners pro- 

 duced (1910) 10 salmon cocoons and 6 white 

 cocoons. 



So much for double matings between Bag- 

 dad Whites and French Yellows. Now for a 

 series between Bagdad Whites and Istrian 

 Yellows. 



In 1907 an Istrian Yellow female was mated 

 from 9 A.M. to 10 :30 a.m. with an Istrian Yel- 

 low male and then from 10 :30 until 12 with a 

 Bagdad White male. This mating produced 

 (1908) 55 yellow cocoons and one (straggler?) 

 white cocoon. Mating (1908) two of the yel- 

 low cocooners produced (1909) 10 white co- 

 coons and 23 yellow cocoons. Mating (1909) 

 two of these yellow cocooners produced 

 (1910) 2 white cocoons and 12 yellow cocoons. 

 Mating (1908) another pair of yellow cocoon- 

 ers of the same Fj lot produced (1909) 13 

 white cocoons and 28 yellow cocoons. Mating 



(1908) still another yellow pair from the same 

 Fj lot produced (1909) 10 white cocoons and 

 24 yellow cocoons. Mating (1909) two of 

 these white cocooners produced (1910) 4 white 

 cocoons and no yellows. Mating (1909) two 

 yellow cocooners of the same F„ lot produced 

 16 white cocoons and no yellow cocoons. 



In 1908 an Istrian Yellow female was mated 

 with a Bagdad White male from 10 :30 a.m. to 

 12 M. and then with an Istrian Yellow male 

 from 12 to 1 :30 p.m. This mating produced 

 30 yellow cocoons. Mating (1909) two of these 

 yellows produced (1910) 16 yellow cocoons and 

 4 white cocoons. Mating (1909) another pair 

 of the Fj yellows produced 19 yellow cocoons 

 and 4 white cocoons. 



In 1907 a Bagdad White female was mated 

 with a Bagdad White male from 9:45 a.m. to 

 11 a.m. and then with an Istrian Yellow male 

 from 11 A.M. to 12 :15 p.m. This mating pro- 

 duced (1908) 15 white cocoons and 57 yellow 

 cocoons. Mating (1908) two of these white 

 cocooners together produced (1909) 11 white 

 cocoons and no yellows. Two other pairs of 

 white cocooners from the same Fj lot pro- 

 duced (1909) small all white lots. From each 

 of these three all white F, lots was mated 



(1909) one pair, and each mating produced 



(1910) a very small weak all white lot. 

 Mating (1908) two yellow cocooners from the 

 original F, generation lot produced (1909) 22 

 yellow cocoons and 6 white cocoons. Mating 



