138 Liheritance in Philosamia Hybrids 



these spots and were called "reduced spots" {R8). The two types were 

 distributed among the 110 imagines as follows : 



RS 



38 28 8 36 



Totals 66 44 



This table shows a preponderance of males among the spotted forms, 

 but further investigation showed that the character was not sex-limited. 



TABLE I. 



Table to show results of various matings in the F^ generation. - 



(?? (?? <?? (J? 



Types of matings... S<->^ -^fxR-S . SxBS RS ^ RS 



Types of larvae ... P S RS P S RS P S RS PS RS 



M 5.6.7.12 ... 76.194.56 _ _ _ 



58. 125. 29 — — — 



Mi.ll — 40.138.36 — — 



— 19. 63.18 — ■ — 

 M 4 — — 18. 44. 23 — 



_ — ,14. 25. 13 — 



1/3.9.10 _ _ — 64.123.49 



— • — —29. 51. 86 

 Ratio of P to SxRS 1 : 3-28 1 : 4-35 1 : 3-72 1 : 3-18 



Ditto l:2-65 1:4-26 1:2-71 1 : 3-0 



The first column contains the numbers given to the matings and used throughout the 

 records ; thus M 5 means mating five. 



The ordinary numerals refer to the larvae and the italics to the imagines. 



The Fi generation. 



Twelve matings produced twelve F^ families, which consisted of 8, 

 RS and P types of larvae in the proportions 3 (S x RS) to 1 P. Every 

 variety of mating (see Table I) was made to test whether S and RS had 

 different hereditary values, but these few matings gave no indication of 

 any difference. It is equally clear that no mating took place between 

 homozygous forms of either /if or RS. This generation only showed that 

 some type of spotted form was dominant. The particular S and RS 

 parents used in these particular'matings appear to have the same inherit- 

 ance value, as judged by their offspring. 



It was observed that there appeared a regularity in the disappear- 

 ance of the spots, for example, when only one spot was lacking, it was 



