THE HUMAN-FLEA. 131 
The eggs hatch in about six days, at least during the 
warmer part of the year. The white larve are furnished 
with feelers and eyes, a very unusual thing in insects. 
Though without feet they move about very rapidly in a ser- 

Fig. 109.—Mouth-parts of human-flea. After Taschenberg 
pentine fashion; they soon turn yellowish, and later they 
gradually become brownish. In about eleven'days they are 
fully grown. Theynowformasort of loosecocoon, composed 
of particles of dust, inside of which they transform into a 

Fig. 110.—Human-flea. Greatly enlarged. Original. 
pupa, which is at first of a white, but later of a brown 
color. After ten to twelve days more the adult flea (fig. 110) 
appears, ready to torment.its host, man. In warmer coun- 
tries the flea passes all these metamorphoses in much shorter 
