SUMMARY OF RESULTS AND CONCLUSIONS 69 



Quantity and quality of silk, subsidiary larval markings, wing- 

 pattern and wing-venation variations, and degree of adhesiveness of 

 eggs are all fluctuating, non-alternative characters. 



Double cocooning is a phenomenon determined by ontogenetic 

 circumstances. Crowding is not the causal circumstance. 



Of various sport appearances of larval, cocoon, and imaginal char- 

 acters only one, namely, larval melanism or moricaudness, is of pre- 

 potent or dominant nature when crossed with the normal condition. 

 All other sport characteristics including various larval color and struc- 

 tural abnormalities, active flight of moths, absence or rudimentary 

 condition of wings, unusual color patterns, including melanism, of 

 moths, are extinguished in cross-matings. 



Fertility is not affected by the age of the egg cells but seems to be 

 unfavorably affected by the age of the spermatozoa. Old spermatozoa 

 seem less potent than younger ones. 



A scientific study of inheritance in silkworms can be of service to 

 commercial silk culture. 



