CONTENTS. 



Introductory Note. 



Races and Characteristics. 



Different Kinds of Inheritance Behavior. 



Alternative Inheritance. 



Larval Color-pattern. 



Cocoon Colors. 



Larval and Cocoon Characters in Same Matings. 



Prepotency of Sex and Vigor. 

 Strain and Individual Idiosyncrasies. 

 Double Mating. 

 Fluctuating Variations and Non-alternative Inheritance. 



Egg Character. 



Subsidiary Larval Markings. 



Wing-pattern. 



Wing-venation. 

 Miscellaneous. 



Double Cocooning. 



Appearance and Behavior of Sports. 



Fertility as Affected by Age of the Germ Cells. 

 Economic Aspects of Silkworm Inheritance. 

 Summary of Results and Conclusions. 



Appendix : Abstracts and Summaries of Papers on Silkworm Biology, 

 Previously Published by the Author. 



Food Conditions in Relation to Sex Differentiation. 



Forced Pupation. 



Loss of Weight During Pupal Life. 



Variations Induced in Larval, Pupal and Adult Stages by Controlled 

 Varying Food Supply. 



Regeneration in Larval Legs and Caudal Horn. 



Influence of the Primary Reproductive Organs on the Secondary Sexual 

 Characters. 



Sex Differentiation in Larvae. 



Moth Reflexes. 



Artificial Parthenogenesis. 



Since 1900 the writer has given attention to the general biology 

 of the familiar mulberry silkworm. This attention has taken the form 

 of considerable experimental work on such problems as the causes and 

 time of sex differentiation, regeneration of larval parts, influence of the 



