644 Laura Florence 



Pediculidae. He points out that the order Anoplura Leach 1817 contains 

 two suborders — Siphunculata Meincrt 1891 and Mallophaga Nitzsch 

 1818 — and says (page 332 of reference cited) : "Since, however, the name 

 Anoplura Leach (1817) was apphed to both Siphunculata and Mallophaga, 

 and in this sense agrees with modern views, it should henceforth be used 

 in its original sense only, tliere being no justification for continuing to 

 apply it to Sipliunculata alone." 



BIOLOGY 



The hog louse is the largest louse affecting domestic animals and is of 

 common occurrence wlierever the hog is found. The hog is its only host, 

 and when not molested the parasite is likely to increase in large numbers 

 and cause an unthrifty condition in a herd. The lice frequent the folds 

 of the siiin on the neclv and the jowl, the inside and the base of the ears, 

 the inside of the legs, the flanlvs, and, in smaller numbers, the baclc, where 

 they crawl under the scales to get in contact with the new skin. They 

 are well adapted for experimental worlv, because they are easj^ of access 

 and feed readilj' on man, while their size and their habit of taking hold 

 of any object placed in front of them lessen the difficulty of keeping them 

 in confinement. 



From the time of hatching, hog lice feed readdj' on man if they have 

 not become weakened through too long fasting. During the course of 

 this investigation hundreds of lice have been fed on the forearm without 

 any resulting reaction, except, in a few cases, a slight redness which 

 disappeared within half an hour, and, in cases in which the mouth parts 

 were inserted but no blood was drawn, a slight swelling which disappeared 

 within an hour. This is contrary to the finding of Sikora (1915:536), 

 who saw no reaction on the first or the second day of the feeding but states 

 that thereafter the skin turned red in an area from 1 to 5 millimeters around 

 the point of puncture and swelled slightlj^, remaining thus for more than 

 twenty-four hours. Recently Moore and Hirschfelder (1919:8) have 

 published a detailed account of serious pathological effects of the bite of 

 the clothes louse and clinical observations of the resulting illness. Accord- 

 ing to Stevenson (1905:12), 



Stockmen handling hogs often become temporary hosts of the louse, but it has never 

 been known to remain for any length of time on the human body and is not known to exist 

 on any animal other than the hog. Attempts made at this laboratory [United States Bureau 

 of Animal Industry] to propagate Haematopinus suis on dogs have met with repeated failure. 



