220 



Diseases of Poultry 



As the disease progresses the mites which are becoming 

 constantly more numerous penetrate very deep into the 







Li. ' ,,j^w 



Fig. 43. — Photograph of the adult female of the mite Knemidocoptes 

 (DerTnatoryctes) Tnuians. (After Haiduk.) 



tissues, causing lameness and sometimes the loss of some of 

 the toes. 



The infection from bird to bird probably takes place on 

 the roosts or from mother to chick. Robinson believes that 



