3QO ECONOMIC ZOOLOGY AND ENTOMOLOGY 



It is believed that the bot-flies of cattle, or the ox-warbles, 

 Hypoderma lineata, and //. bows, gain an entrance into the ali- 

 mentary canal in the same way, that is by being licked from the 



FIG. 177. Bots, larvae of Gastrophilus equi, in stomach of horse. 



(Enlarged.) 

 i 



hairs on the body where the eggs have been laid by the adult 

 fly. But instead of passing on into the stomach they penetrate 



FIG. 178. Ox warble-fly, Hypoderma lineata. (About two and one-half 

 times natural size.) 



the Walls of the esophagus and later make their way through the 

 tissues of the body, until at last they reach a place along the 

 back just under the skin. Here, while completing their 



