328 



ANIMAL LIFE 



human oil glands supplying the hair. The microscopic 

 itch mite buries itself beneath the skin and causes the 

 disease of itch. Several other species of mites affect the 

 domestic animals and cause the falling out of the hair 

 and other disturbances. 



The cattle tick (Boophilus boms) affects the cattle of 

 the Southern states, Mexico, and Cuba. Like many 

 external parasites, it sometimes leaves one victim to 



PIG. 368. The cattle tick, female and male. Much enlarged. After Howard. 



attack another later, and in so doing transfers the germs 

 of disease from the sick to the healthy. The cattle tick 

 has thus been found to be the chief if not the only means 

 of spreading the fatal Texas fever among herds of cattle, 

 and it is on this account that all cows shipped north must 

 first pass through the dipping tanks of petroleum or other 

 insecticidal liquid. Several species of ticks affect the 

 domestic animals. 

 The lice, of which there are more than forty species 



