THE BOTS 83 



ciously do they adhere, that the hook will break before 

 they leave their hold. There these pests contrive to 

 locate during the whole winter, and to the end of the 

 following spring, feeding on the mucus ; by which 

 time they have grown to full size (fig. 5), and must 

 now undergo a new transformation ; they quit their 

 hold of the coating of the stomach, are carried into 

 the villous portion along with food, from thence pass 

 into the intestinal canal along with the chyme, and at 

 length are discharged with it. The caterpillars thus 

 evacuated seek an appropriate place in the ground, 

 where they assume the imago or chrysalis condition ; 

 and remaining in this state for some weeks, at length 

 break out from their swathing and assume the form of 

 the perfect insect. Immediately after this the males 

 and females pair ; the latter becoming impregnated, 

 set about seeking an appropriate situation where to 

 deposit their eggs, which, in imitation of the parent, 

 by a peculiar instinct, they fix on the hairs of a horse, 

 from whence they are licked off and swallowed in the 

 larva state. 



There are two species of gad-flies ; the second is 

 known by the name of the red bot, fig. 6 is its larva, 

 and fig. 7 the perfect fly. Their natural history and 

 habits are similar in all respects to the other. 



