PARASITIC DISEASES OF CATTLE. 



909 



the lancet, for the more easy ex|iulsion of the grubs. The cuts show the 

 two forms of the insect, — the perfect fly and the grub. 



III. Lice. 



Vrrious species of lice infest the ox, the principal being the ox louse 

 proper, the calf louse, (both of which are species of Jloematopinus, or 

 blood suckers), and a certain kind of bird louse, one of the tribe of 



CALF LOUSE. 



BIRD LOUSE. 



APPEARANCE OP A COW AFFECTED 

 WITH LICE. 



Trichodecies, having no sucking tul)e, but with strong biting jaws. The 

 cixts show all these parasites, of course very much enlarged. 



There are also ticks infesting 

 cattle at certain seasons, and espec- 

 ially plentiful on Texas cattle. Of 

 the several varieties founci, the one 

 known as the Texas tick {Boophihis 

 Bovis) is the most important, it 

 being the cause, at least of the 

 transmission, of Texas fever. The 

 -emale attaches herself to the animal where the skin is thin and soft — on 

 the insides of the thighs, along up to the anus, just back of the elbows and 

 .>n the neck back of the ears — by burying her head into the skin, is fecunda- 

 ted by the male, which dies immediately after, and remains there till mature 

 if not pulled or rubbed off, then she drops off 

 and hides under a crust, where she lays her eggs 

 and dies. The young ticks hatch out in a few 

 days, and, being very active, get on to the cattle 

 as opportunity offers, and so the round is con- 

 tinued. These ticks contain the germs of Texas 

 fever, and they spread the disease through their 

 bites. The accompanying cut shows the Texas 



tlOlF o TRXAf TICK. 



