64 INHERITANCE IN SILKWORMS, I 



quantity of silk to total weight of cocoon and enclosed pupa) is purely 

 a fluctuating characteristic, capable of a certain amount of amelioration 

 by persistent, rigid, personal selection. Double cocooning is a char- 

 acteristic, from the evidence of my data, not heritable but ontogenetic, 

 although from the statements of Duseigneur and Lambert it would 

 seem to be heritable ; it is a characteristic needing more study to deter- 

 mine its actual behavior or status in inheritance. 



But it is, as said in the introductory paragraphs of this paper, not 

 my intention to consider at present in any detail the economic aspects 

 of our present knowledge of the status in inheritance of the characters. 

 I hope to be able in a future paper to offer some discussion of this 

 subject. 



