SOME HUMAN PARASITES 309 



at the sudden transportation into congenial surroundings 

 for the first moment eclipse everything else, hunger soon 

 asserts its claim, sharpened as it is by the long fast, which 

 has rendered its stomach and intestines quite transparent. 

 The animal raises itself on its legs, walks on a few steps, 

 seeking and feeling its way with its antennae, while we 

 followed it with a magnifier. Presently it stops, draws 

 in its legs a little, arches its back, bends the head down 

 toward the skin at an oblique angle while it probes a small 

 dark and narrow organ repeatedly forward, and draws it 

 back through the fore end of the head ; at last it stands 

 still, with the point of the head firmly abutted against the 

 skin." While in this position the rostrum was buried in 

 the flesh, and the louse was pumping out the blood. 

 Schiodte describes in detail the work of the louse in obtain- 

 ing its supply of food. He made an attempt to dislodge 

 the insect in such a way that its beak would still be ex- 

 tended. As soon, however, as the louse was dislodged from 

 the flesh, it immediately withdrew the beak into the head 

 so that it could not be seen. Finally, he quickly severed 

 the head of the insect from its body, and succeeded in 

 mounting it with the rostrum still extended. There was 

 a long tube furnished with hooks near the base. Inside of 

 the tube could be seen four slender thread-like projections. 

 This structure evidently formed a very efficient pumping 

 apparatus. 



THE HEAD LOUSE 



Pediculus humanus (capitis) 



This species occurs chiefly among the hairs of the head 

 although it is occasionally found on other parts of the 



