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The Journal of Heredity 



This difference is probably due to the 

 fact that the larva of Rhopalomyia is 

 almost twice as large as that of the sec- 

 ond host, and thus furnishes a better 

 supply of food for the multiplication 

 of embryos. The smallest brood found 

 contained five individuals (Brood 68), 

 the largest thirty-seven (Brood 21). 

 Table lll.-Mixed Broods of Paracopidosomopsis 

 (Per cent of Males Based on a Study of 500 Individuals] 



In many respects the data collected 

 on Platygastcr are the most interesting 

 available for any polyembryonic spe- 

 cies. So far not a single male brood has 

 been found. Perhaps a larger collection 

 of data would reveal such broods. The 

 scarcity or absence of pure male broods 

 can be explained as follows : The car- 



Table IV. — Broods of Platygaster from 

 Rhopalomyia. 



