1 is 



HEREDITY AND SEX 



OPERATIONS ON INSECTS 



The Ensects constitute the third great group in which 

 secondary sexual characters are common. 



The firsl operations on the reproductive organs were 

 caiiicd out by Oudemans on the gipsy moth, Ocneria 

 Parthekria i dispar. The male and female are strik- 

 ingly different. Oudemans removed the testes from 



Fig. i 1. i»\arii> of Lymantria (.Porthetria) dispar transplanted to male. 

 They have established connection with the sperm ducts. (After Kopec.) 



young caterpillars and found no change in the color, or 

 size, of the male. He also removed the ovaries from 

 young caterpillars, and again found no effect in the fe- 

 male. The same experiments were later carried out on 

 a large scale by Meisenheimer, who obtained similar 

 results. Meisenheimer went further, however, and per- 

 formed another operation of great interest. He removed 

 the male glands from a male and implanted in their 



