132 



AN INTRODUCTION TO ENTOMOLOGY. 



some on ships, in military camps, in prisons, and in the apartments 

 of uncleanly people who neglect to change their clothes. The fe- 

 male attaches her eggs to fibres in the seams of undergarments, 

 from which the larvae hatch in about a week. This species is ex- 

 ceedingly prolific. The method of destroying these vermin com- 

 monly employed in hospitals and poorhouses is to rub mercurial 

 ointment in the seams of undergarments. 



The Crab-louse, Pkthirius pubis. The common name of this spe- 

 cies is suggested by the form of the body, which is nearly as broad 

 as long. When highly magnified, the resemblance of this insect to 

 a crab is quite striking ; but to the unaided eye it appears more like 

 a large scale of dandruff. These offensive vermin affect the pubic 

 region and armpits of man, stretching themselves out flat, holding 

 tight to the cuticle, and inflicting most irritating punctures. They 

 can be destroyed by mercurial ointment. 



The true lice of cattle, of the horse, ass, swine, squirrel, etc., are 

 very closely allied to the head-louse and body-louse of man. They 

 have been placed, however, by systematists in a distinct genus, 

 Hcematoplnus. The names of the more important species are as fol- 



FIG. 116. H. eurysternus. FIG. 117. H. vituli. 

 (From Law.) (From Law.) 



FIG. 118 H. SMJ'S. 

 (From Law.) 



FIG. ng.ff. piliferus. 

 (From Law.) 



lows: louse of cow, H. eurysternvs (Fig. 116); a second species 

 found on cattle, especially calves, is H. vituli (Fig. 117); louse of 

 horse and ass, H.dsini (Fig. 115); louse of swine, H. suis (Fig 1 1 8) ; 

 louse of the dog, H. piliferus (Fig. 119); louse of rabbit, H. ventri- 

 cosus ; louse of monkeys, H. quadrumanus. 



