292 



OSV. POLIMANTI 



TABLE 

 Summary of Experiments 



From this table it is evident that the greater number of the 

 males of Bombyx mori soon after emerging from the cocoon 

 attached themselves to cocoons from which afterward came 

 female moths. A large number, however, attached themselves 

 to cocoons from which came male moths; only a small number 

 of females attached themselves to cocoons containing male 

 moths, and none to those holding female ones. Lastly, a num- 

 ber (15)% of both males and females attached themselves suc- 

 cessively to cocoons containing moths of one sex or the other. 

 These are, in short, individuals uncertain of their choice and 

 which, of course, we cannot take into account in these experi- 

 ments because they do not forward our conclusions. 



I have observed, further, that when a moth, either male or 

 female, attaches itself to a cocoon from which later emerges a 

 moth of either the same or different sex, it produces always the 

 same number of vibrations of the wings; that is to say, what- 

 ever may be the sex of the moth in the cocoon, the free moth 

 causes its wings to vibrate in that given and determinate rhythm 

 with the certainty that there is in the cocoon an individual of 

 the opposite sex. 



From these experiments we may concluded that the theie- 

 perception of sex (olfactory?) in the moth of Bombyx mori is 

 not well developed. The membrane of the cocoon may oppose 

 too great an obstacle to the characteristic olfactory vibrations 

 which come from the female. It seems, then, that such a mem- 

 brane is enough to prevent such vibrations. 



