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Vou. IX. DETROIT, APRIL, 1889. No. 4 
ORIGINAL COMMUNICATIONS. 
THE ACARUS FOLLICULORUM IN THE HUMAN SKIN.* 
CHEVALIER Q. JACKSON, M. D. 
[PLATE tv. | 
OBBOLD, in the introduction to his admirable, though con- 
tracted work on Entozoa, writes : 
‘“‘ Whatever notions people may entertain respecting the dignity 
of the human race, there is no gainsaying the fact that we share with 
the lower animals the rather humiliating privilege and prerogative 
of entertaining a great variety of parasites.” 
Now prominent among these parasites is the Acarus folliculo- 
rum, or as it is more commonly, though less advisedly, called, Demo- 
dex folliculorum. And since probably two-thirds of the members of 
this society have each some thousands, more or less, of these para- 
sites in the sebaceous follicles of their skins, a few remarks on the 
mite may not prove uninteresting. 
In 1841, Henle described this little octozoon in the secretion 
commonly known as ‘“ ear-wax,” of the external auditory meatus. 
Independently of this, in 1842, Dr. Simon, a German physician 
announced in the June number of Miiller’s Archiv, his discovery of 
Demodex folliculorum in the unctuous plug of hardened secretion 
which, under the ordinary local conditions, occupies the ducts of the 
oil-glands of the skin. In the latter part of the same year, Wilson, 
the father of dermatology, communicated to the Royal Society the 
* Read before the Iron City Microscopical Society, January 8, 1889. 
