50 BOARD OF AGRICULTURE. 
least three times, at intervals of three or four days, to destroy 
the young as fast as they hatch. 
Species of Sarcoptes, closely allied to the itch-insect, have 
been found on the domestic animals, causing diseases analo- 
gous to the itch in man. Such diseases, caused by quite a 
number of distinct parasites, are called “mange.” They 
have been observed on the cat, dog, camel,* and ‘hog. 
The genus Dermatodectes is closely allied to Sarcoples, and 
the species likewise live on animals, burrowing in the skin. 
D. bovis infests cattle, and D. ovis lives in the skin of sheep. 
The genus Dermaleichus infests birds in a similar manner. 
All these parasites should be treated like the itch-insect of 
man. The sulphuret of potassium solution, applied with a 
brush that has long bristles, like a white-wash brush, is 
probably the best and simplest remedy. 
The Face-mite (Demodex folliculorum Owen). Figure 48. 
This singular but minute parasite lives in the discased and 
enlarged follicles in the skin of the human face, especially in 
those about the nose and chin. The follicles, when thus dis- 
eased, are enlarged and filled with a thickened 
sebaceous matter, the orifice being usually ob- 
structed by a hardened, blackish substance. If 
these be pressed, and the matter which is forced out 
be carefully examined with a microscope, it will often 
be found to contain numerous specimens of this minute 
creature, in all stages of development. A drop of 
oil or ether applied to the sebaceous matter, to 
dissolve the fatty parts, will render them more 
readily visible. The young ones have but six short 
legs; the adults have eight legs and a worm-like 
body, as represented in Figure 48. It has been thought that 
the “barber’s itch” is caused by this parasite, but I do not 
know that this has been fully established. 
Figure 48. 
*S. dromedarit, of the camel, is sometimes communicated to man, causing a 
form of itch worse than the ordinary, owing to its great size and numerous spines. 
‘ 
Figure 48.—Face-mite (Demodex folliculorum Owen, or Sinonea folliculorum of 
some authors), much enlarged. From Packard’s Guide. 
Digitized by Microso: 
