NATURAL HISTORY PAPERS. 109 



ance on the front of its head. This protuberance contains 

 a sucker which is forced out at will. "When extended it 

 is a tube terminating in six little pointed hooks curving 

 backwards thus serving to return it in the skin of its vic- 

 tim. At the end of this sucker and in its interior are 

 four fine hairs joined together in a peculiar manner appa- 

 rently calculated to aid in the process of extracting the 

 blood from the scalp, ])ut in what manner they act is not 

 known. The thorax is nearly square and divided into 

 three pai-ts by deep incisions. The abdomen is composed 

 of eight rings or bands extending round the insect. They 

 have six legs, all terminating in a peculiar strong nail 

 that folds back into an indented projection, thus forming 

 a pincer by which the louse fastens itself to the hair, 

 clinging with great tenacity. 



In their reproduction they are oviparous. Their eggs 

 which remain sticking to the hair are long and white, 

 commonly called "nits." The young, hatched in five or 

 six days, and in about sixteen or eighteen days are able 

 to reproduce their kind. Yet their fecundity is so great 

 that it is calculated that under favorable circumstances, 

 this species is capable of producing in forty days at 

 least one hundred and tMcnty-five thousand fiom a single 

 pair. Happily for the victims of this disgusting parasite 

 their reproduction is not usually to any such extent. 



Another species, the Pediculus humanus corporis, ex- 

 ceeds the Pediculus capitis in reproductive powers, ma- 

 ny hundred times, but happily f(n- the human family it is 

 not as common. This species causes a fungous growth or 

 disease of the skin called piti/ricms, and though not com- 

 mon at the present day, like the leprosy, was a terror to 

 the ancients, and with reason. They not only infested 

 the poor, but the rich and learned were susceptible, and 

 history informs us of numerous instances of death from 

 this disease. King Antiochus, it is stated, was so cov- 

 ered with lice before his death that his skin was a crum- 

 ling mass of them, and baskets-full were scraped ofi' and 



