84 Parasitic Arthropods 



carbolic quickly disperses. At the end of this period every pedicu- 

 lus and what is better, every ovirni is dead and no relapse will occtir 

 unless there is exposure to fresh contagion. Whitfield states that 

 there seem to be no disadvantages in this method, -which he has used 

 for years. He has never seen carboluria result from it, but would 

 advise first cutting the hair of children under five years of age. 



Pediculus corporis ( = P vestimenti) the body louse, is larger than 

 the preceding species, the female measuring 3.3 mm., and the male 

 3 man. in length. The color is a dirty white, or grayish. P. corporis 

 has been regarded by some authorities as merely a variety of P- 

 humanus but Piaget maintains there are good characters separating 

 the two species. 



The body louse lives in the folds and seams of the clothing of its 

 host, passing to the skin only when it wishes to feed. Bnmipt 

 states that he has found enormous numbers of them in the collars 

 of glass-ware or grains worn by certain naked tribes in Africa. 



Exact data regarding the life-history of this species have been 

 supplied, in part, by the work of Warburton (1910), cited by Nuttall. 

 He found that Pediculus corporis lives longer than P. humanus under 

 adverse conditions. This is doubtless due to its living habitually 

 on the clothing, whereas humanus lives upon the head, where it has 

 more frequent opportunities of feeding. He reared a single female 

 upon his own person, keeping the louse enclosed in a cotton-plugged 

 tube with a particle of cloth to which it could cling. The tube was 

 kept next to his body, thus simulating the natural conditions of 

 warmth and moisture luider which the lice thrive. The specimen 

 was fed twice daily, while it cltmg to the cloth upon which it rested. 

 Under these conditions she lived for one month. Copulation com- 

 menced five days after the female had hatched and was repeated a 

 number of times, sexual union lasting for hours. The female laid 

 one hundred and twenty-four eggs within twenty-five days. 



The eggs hatched after eight days, under favorable conditions, 

 such as those under which the female was kept. They did not 

 hatch in the cold. Eggs kept near the person during the day and 

 hung in clothing by the bedside at night, during the winter, in a cold 

 room, did not hatch until the thirty-fifth day. When the nymphs 

 emerge from the eggs, they feed at once, if given a chance to do so. 

 They are prone to scatter about the person and abandon the frag- 

 ment of cloth to which the adult cHngs. 



