202 ARACHNOIDEA. 



CASE There are many species that go by this name, but no doubt the 

 majority belong to the genus Amblyomma. They are common in 

 all parts of South America where cattle abound ; and they not 

 only attack cattle but also horses, dogs, and sheep, and occasionally 

 man himself. Like our own ticks they are found on plants, and 

 when cattle become infested with them it is generally after feeding 

 on open and exposed pastures, where the sun's heat is great ; and 

 they increase most in dry seasons. 



It is generally, but we may be sure erroneously, supposed that 

 the insect was not seen in the Brazils previously to an excessively 

 hot and dry summer, about 1824 or 25, since which it has multi- 

 plied amazingly. It is remarkable that cattle feeding in shady 

 pastures and coppices are frequently quite free from the carapato, 

 but will acquire it by infection from others. The mode in which 

 it appears to cause destruction to the animal infested by it, is by 

 the incessant irritation, which prevents the animal feeding or rest- 

 ing, and in consequence it becomes worn out. Many thousand 

 head of cattle are annually carried off by them, and even a scarcity 

 of food has been caused by them. Prof. Busk, from whom we 

 take some of these details, in describmg the young of one species 

 (Trans. Micr. Soc, vol. I.) and the mischief that they do, 

 mentions that " they first appear on those parts of the skin un- 

 covered by hair, and are then not larger than a pin's head, and 

 make the part quite black by their numbers. They adhere so 

 closely, that scraping them off would tear off the skin. In a short 

 time they increase to the size of a bean, or common tick, as seen 

 in dogs, and fix themselves promiscuously on all parts of the hide, 

 where covered with hair. 



" The same species 'appears to insinuate itself in its incipient 

 state, upon the human body, but is not known to assume the tick 

 form there (doubtless because not allowed to remain). They 

 adhere most tenaciously to the skin ; and, he says, they are 

 beheved to introduce themselves below it, and are very harassing 

 and even create soreness and inflammation. They generally 



