PARASITOLOGY. 49 
the leaves of vegetation by man or animal, when it 
buries itself in the skin and produces intense itching. 
Treatment.—lf the affected part be touched with a 
one-percent solution of formalin it will kill the para- 
sites and stop the itching; or, the parts may be 
touched with a two-percent solution of aqua ammo- 
nia. 
SARCOPTIDAE. 
The three principal genera of the sub-family Sar- 
coptidae are: 
Sarcoptes (Sarco—flesh; kopto—to cut). 
Psoroptes (Psora—itch). 
Symbiotes (Sym—togather; bios—life). 
The Sarcoptes live on the body where the hair is 
short,—in horses and dogs on the body ; in sheep, on 
the facial regions. 
The Psoroptes live on the body where the hair is 
long,—in horses and cattle in the mane and down the 
back ; in sheep, on the body. 
The Symbiotes live on the extremities,—legs. 
GENERAL DESCRIPTION OF THE FAMILY. 
Minute in size; the body is oval and obtuse at both 
ends, convex above and flat below; the mouth parts 
are provided with a single lancet-shaped piece, sur- 
rounded by palpi; the legs are divided into five arti- 
cles each, the free extremity of the last segment 
is provided with an ambulacrum or one or two hairs. 
The genus Sarcoptes, species Scabei, is provided 
with a head as broad as it is long; the rostrum is 
short, and is margined by two cheeks. 
Male.—The first, second and fourth pair of legs 
