330 



ANIMAL LIFE 



the alimentary canal or just beneath the skin of the mam- 

 mals. The young of the horse bot dwell in the stomach, 



FIG. 371. Anopheles, the parasitic mosquito, infecting man with the malaria 

 germ. Photograph enlarged three times. 



while those of the cow migrate, as soon as hatched, from 

 the alimentary canal to the back, just beneath the skin, 

 through which they make holes to 

 breathe and later escape. 



All of the ichneumon flies, of 

 which there are more than a thou- 

 sand species, are parasitic in other 

 insects during the larval state. 

 Their presence usually means death 

 to the host. . They are, therefore, 

 of great service in keeping in check harmful species, such 

 as the cabbage worm, tussock moth, fall webworm, and 

 cotton caterpillar. Out of a hundred larvae of moths and 



FIG. 372. Larva of the ox 

 bot (warble) removed from 

 beneath the skin of the back. 

 Photograph life size. 



