MALLOPHAGA 



253 



zoological interest of the MaBopfaaga lies m tbe attempt 



been made to use diem in avian taxoooonr. Since tibe UmiSrs of 



lice are in general restricted to particular groaps ai birds^ it hsas 

 been suggested that wben the afcntjps of tbe Ike are dearer tkaa 

 those of the birds, the classi&caticm of the birds may be based 

 on that of the Hce. 



Ord^ 15. Anopleura. The sadoDg hce. or smply hce, are 

 wingless ectoparasites of ntammals and have pier : r : - _ - - -parts, 

 Two species are found on man. Pedicidus s (Fi^. 1S51 



LZ-i Pktkirus pmbis (Fig. i^c . The latter, the crab or pubic 

 louse, is found chiefly, though not solely, on the hairs of the pobtc 

 region, and is of no great 

 medical importance. P. 

 k%mumus occurs in. two 

 forms, the r : iy louse, 

 P. hun cotpowis, 



found only on the body 

 and its clothing, and the 

 head louse, P. hmwumus 

 capitis y found on tbe 

 bead and occasionally 

 elsewhere. These were 

 formerly amsidered to 

 be different species. Both 

 transmit the parasites 

 which cause t\'phus. 

 trench fever, and re- 

 lapsing fever, the first two being organisms of 

 Rickettsia, and the third the bacterium Trefomfma [ =5^w»cW«t> 

 recurrentis. Lice are common in almost all crowded alienations 

 of man, whether they be primitive tribes, urban schools, or prisons. 

 An\-thing which leaves the hce to a peaceful life, such as Tin- 

 changeddothes. or long hair (and especially p^maneiLt waves*, 

 will encourage them, but the indi\-idual infestation is seidoaaMOie 

 than twenty. Since neither the insects nor their eggs can h\^ 

 long away from man, the chief method by which the paraates 

 spread is personal contact. Infection may. however, take place 

 through towels or combs or stray hairs, especially when these 

 bear the eggs or nits, and since the Hce can move at about nine 

 inches per "minute, propinquity to an infected person is almost as 

 dangerous as contact. Lice may be completely remo\-ed from tbe 



Fig. 



1S6, — TTie crab lo«ase (Pifctfctr»s pmkik^. — 

 From Sedgwick, aiter LaxL-dois. 



5t, Sdgsnsa ; Tr^ tracaea. 



