vni LICE 60 1 



by three species, Peclicidus capitis, P. vestimenti and Fhthirius 

 ingwinalis ; Meinert is of opinion that P. capitis and P. vestimenti 

 are only one species, and Schiodte appears also to have thought 

 this probable. Andrew Murray was of opinion that the heads 

 of different varieties of men are infested by distinct varieties of 

 P. ccqntis. His conclusion was chiefly based on examination of 

 specimens preserved by Charles Darwin ; it requires confirmation. 

 Very little is known as to the life-history of the louse. Leeuwen- 

 hoek made himself the corpus vile for an experiment, from which 

 he concluded that the Pediculus vestimenti is very prolific. That 

 scientific men did not know whether the louse bites or sucks was 

 formerly made the ground for a taunt. Schiodte has given an 

 almost pleasing account of the way in which he settled this,^ 

 showing that the sucking action is beyond all doubt. Accoimts 

 of disease called Phthiriasis, attributed to lice, are to be found in 

 many old books, but the evidence does not warrant us in believing 

 anything more than that persons suffering from some disease, and 

 in a neglected and filthy condition, were horribly infested with 

 these disgusting Insects. 



It is usual to say that Pediculidae are Hemiptera degraded by 

 a long exclusive persistence in parasitic habits. At present, 

 however, this must be looked on as a pious opinion, rather than 

 as an induction from our knowledge of their morphology and 

 embryology ; for this is at present too imperfect to warrant any 

 final conclusion. 



1 Ann. ^^at. History (3), xvii. 1866, p. 213. 



