148 



HEREDITY AND SEX 



OPERATIONS ON INSECTS 



The Insects constitute the third great group in which 

 secondary sexual characters are common. 



The first operations on the reproductive organs were 

 carried out by Oudemans on the gipsy moth, Ocneria 

 {Porthetria) dispar. The male and female are strik- 

 ingly different. Oudemans removed the testes from 



Fig. 74. — Ovaries 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 



