108 NATURAL HISTORY PAPERS. 



the animals it selects for its prey. The pig and dog seem 

 to enjoy the preference, yet most nuinuils are infested 

 more or less and there seems to he a little variation of 

 the order in different animals, bnt not snfficient to re- 

 <piire mention here. 



PuLEX rEXETiiANS. — There is however the chierre or 

 j'lgiXor (T*i(hx 2)enef vans) of the AVest Indies, whi^-h departs 

 consideraI)le from the varieties above mentioned. It is 

 much smaller, flat, brown, with a white spot upon its 

 back, and armed with a beak provided with three lancets. 

 AVith these the female makes an incision into which she 

 creeps. Iodising in the skin and bringing forth her young 

 there. This makes a painful sore and the insect has to be 

 extracted. 



The chigres are an object of terror to the natives of warm 

 countries which they infest, as they sometimes attack a 

 limb in such numbers as to bring on mortification, and 

 even death. Man}' of the Brazilian Xegroes are perma- 

 nently disabled from this cause. The lai-vte do not live 

 eitlu'r in the body of the parent or of its host, but are 

 pushed out, falling upon the ground where their transfor- 

 mations are like those of Pultx irritansy whose progeny 

 they then resemble. 



Family, — Pediculid^. 



Pediculus capitis. — Though the Louse is common to 

 almost all animals, a description of this species answer to 

 a great extent for all. This insect has a flat bpdy, slight- 

 ly transparent, and Spotted with black, soft in the middle 

 but rather hard at the sides. The head which is oval is 

 furnished with two thread-like antennai composed of five 

 joints which are constantly in motion Avheu they are walk- 

 ing ; it is also furnished Avith a pair of jet black eyes, and 

 with one of the most peculiar mouths that insects have. 

 AVhen at rest its mouth seems to form a little protuber- 



