34 



CLASS ARACHNIDA 



stage. In the adult stage still another host is sought, this 

 time usually some of the larger animals, such as domestic 

 cattle or sheep, and i)r()bably in the wild condition such 



Fig. 15. — Psoroptes communis, var. cgui. (Reduced from Furstenberg, 

 after Murray.) 



animals as the antelope or Rocky Mountain sheep or other 

 ruminants of the Rocky Mountain region. On these hosts 

 fertilization occurs and the females then drop to the ground 



