SUCKING-T.ICE. 



95 



ter were sucli a conimon occurence that few school rooms 

 could boast of not having such inhabitants. It shows that 

 civilization after all depends largely upon the frfee use of soap 

 and some mechanical appliances as fine-toothed combs. 



Lice are true insects furnished with a sucking mouth 

 (fig. 65). They are very degraded insects, how^ever, and do 

 not even possess wings, for w^hich they have no use, being 

 generally surrounded in their dwelling-places by plenty of 



Fig. 65. — Mouth-parts of body-louse; a, a, summit of head with 

 bristles; b, b, the chitonous band; c, hind part of lower lip; d, d. 

 protruding part of lower lip (hanstellum); e, e, hooks turned out- 

 wards; /', inner tube of suction, with two pairs of ja-ws shown as 

 lines on the outside, and a few drops of blood in the interior. 

 Greatly enlarged. After Schicedte. 



food. The small head is conical; the thorax is also small 

 and indistinctly segmented; the abdomen, ho^wever, is large, 

 flat, round or oval, and contains nine segments. The slen- 

 der feelers possess five joints; the simple eyes, if they possess 

 any, are minute; the feet have two joints, of which the last 

 one forms a strong hook for grasping the hairs w^hile climb- 

 ing upon them. The mouth forms a very slender, fleshy 



