144 INFECTIOUS AND PARASITIC DISEASES. 



actively motile as when ordinarily seen in decomposing 

 material. Solutions of bichloride of mercury (i-iooo) 

 quickly rid the host of these parasites. 



Or common flea is a minute red or dark- 

 PuLEx brown insect which is only parasitic upon 



Irritans. man in countries where it is present in 



great numbers. It is particularly trouble- 

 some in hot countries. Its eggs are not laid 

 in the skin, but in cracks of floors, sawdust 

 and dust. Its bites are irritating and may 

 cause wheals (hives). 



The sand-flea, "jigger," "jig- 

 Sarcopsylla ger-fiea," "chigoe" or "chique" 

 (pulex) is a more serious parasite than 



Penetrans, the common flea. The impreg- 

 nated female burrows into the skin to breed ^ ^^^- l^- ~~ 



Larva of pu- 



her young, which are very numerous. Favor- lex irritans, 



1 , . . , (Gould.) 



ite situations are the lower extremities and 

 feet, particularly beneath the nails of the toes. Painful 

 swellings, abscesses, and ulcers often result. The in- 

 sect is principally found in Central and South America, 

 and South Africa. The fleas may be picked out with 

 a needle, but one should be careful to extract them 

 whole since distressing sores may otherwise result. 



Bed-bugs are true cosmopolitans, being 

 CiMEx found the world over. The body is thin 



Lectularius. and flat and oval in outline. Its color 



varies from a grey to a dark reddish- brown. 



