SCABIES. 



687 



the creature may be seen to swallow minute bubbles of air, 

 which pass down the c^sophagus, and, like the nutritive juices, 

 diffuse themselves through the interior. At all events, animal 

 juice and air are both necessary to the life of the acarus." — 



(BOURGUIGNON.j 



Tig. 119. 



Fig. 117 — Dorsal surface of the female acanis scabie. 



Fig. 118.— Ventral ,, ,, ,, ,, 



Fig. 119, — Ventral surface of the male acarus.— (Bourguignon.) 



100 diam. 



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

 human skin. All the male acari 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 eats its way between the scales into the deeper layers of the 

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

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

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



