LIFE HISTORY 



257 



which first suggested the name " hookworm " for the parasites, 

 though the hookhke teeth in the mouth of the Old World species 

 might just as readily have suggested the name. 



Fig. 102. Bursa of American hookworm. (After Stiles.) 



B(X'50) 



Fig. 103. Life history of hookworm; A, adults, female and male, in intestine; 

 B, egg as paiBsed in faeces: C, embryo hatching in ground, 24-48 hours later; D, 

 fully developed larva, enclosed in sheath, ready to infect human being; E, larvae 

 relea.sed from sheath, migrating in body of new host. 



Life History. — (Fig. 103.) The female worms produce an 

 enormous number of eggs which are poured into the intestine of 



