702 



SCABIES. 



the crefttnre may /b© seen to swallow minute bubbles of air, 

 which pasa down the ccsophagus, and, like the nutritive juices," 

 diffuse themselves tlirough the interior. At all events, animal 

 juice and air are. both necessary to the life of the acarus^' — i 

 (BOURGUIGNON.) 



Fio. 127. ! 



Tta. 125 — Dorsal etirfaoe of the female acarua acabie. 



Fro. 126.— Ventral ., „ „ „ 



^la. 127 —Ventral surface of the male acarus. — iBoDBatnoKos.) 100 diam. 



It is the female only which burrows in the epidermis of the 

 human skin. All the male acan go free on the surface of the 

 epidermis, where sexual intercourse between male and female is 

 said to take place. Wlien an impregnated female is placed on 

 the surface of the skin, it seeks a suitable spot to penetrate, and 

 raising its head at right angles to the surface, it burrows, digs, 

 or eata its way between the scales into the deeper layers of the 

 epidermis, where it imbeds itself, derives nourishment, and goes 

 through the process of partnrition, till it dies. Having found a 

 suitable place, an egg is laid, and each day another, the animal 



