6o 



THE INSECT WOKID, 



carried away with the excrementitious matter It traverses mixed 

 with the excrementary bolus, the whole length of the intestinal canal, 

 leaves it by the anal orifice, and on touching the ground at once 

 seeks a suitable place to go through the last but one of its 



"^^ T^heTkin'then gets thick, hardens, and becomes black All the 

 organs of the animal are composed of a whitish amorphous pulp 

 which soon assumes its destined form, and the msect becomes penect. 



Fig 45.— Bot-fly {iEstyus Iwvi's). 



It then lifts a Hd at the anterior part of its cocoon, emerges, dries its 

 wings, and flies off. , • 1 j i 



The Bot-fly {CEstrus bovis, Fig. 45) has a very hairy body, large 

 head, the face and forehead covered with light yellow hair, the eyes 

 brown, and the antennse black. The thorax is yellow, barred with 

 black ; the abdomen of a greyish white at the base, covered with 

 black hair on the third segment, and the remainder of an orange 

 yeUow ; the wings are smoky brown. , • . j 



As soon as the cattle are attacked, they may be seen, their heads 

 and necks extended, their tails trembling, and held m a Ime with the 

 body, to rush to the nearest river or pond, while such as are not 

 attacked disperse (Plate II.). It is asserted that the buzzing alone ot 



