MUSEUM OF COMPARATIVE ZOOLOGY, 13 
follicles of the external auditory canal of dead human subjects, and the 
first notice of it appeared in the “ Oeffenlicher Beobachter " of Zürich in 
December, 1841, in a report of a meeting of the Naturalists’ Society of 
that place.* Henle completely misunderstood the nature of the parasite, 
which he was inclined to place in the neighborhood of Polystoma, mis- 
taking the legs for the suckers of the Trematode, the head for the tail. 
He gave it no name. 
About the same time, the mite was observed independently of Henle 
by Gustav Simon, a physician of Berlin, who published a very careful 
description of it, together with figures, in Müllers Archiv for ٩ 
It was in the course of his studies of certain diseases of the human skin 
(Acne, Comedo) that Simon discovered the parasite in both diseased and 
healthy hair-follicles in the nose of living and dead subjects. Erichson, 
who was consulted by Simon with reference to the zodlogical position of 
the newly discovered animal, placed it among the mites, and named it 
Acarus folliculorum. Simon included in his description and figures the 
young form of the animal, which has but three pairs of legs, and. also 
what he thought to be the egg-shell. In the following year, 1843, 
Owen,t without making any new observations, fixed the position of the 
animal more precisely, making it the type of a now genus, Demodex, and 
during the same year Miescher $ published a description of it under the 
name Platypus macrogaster. || 
Erasmus Wilson, also in 1843, made extensive studios upon the 
structure and development of this animal, and his results were published 
in the Philosophical Transactions of the Royal Society for 1844. He 
found it in the hair-follicles and sebaceous glands of healthy as well as 
of torpid skins, commonly in the face, but also in the back, breast, and 
abdomen, 
account of our parasite found in the cerumen of theear. He put it among the Tardigrades, 
and no name was given it, Comptes Rendus, XX. p. 1506,1845. Froriep's Neue Notizen, 
XXXV. p. 58, 1845.) 
* Teste Miescher. 
T “Ueber eine in den kranken und normalen Haarsiücken des Menschen lebende Milbe.' 
Arch. f. Anat. Physiol. u. Wissensch. Med, 1842, pp. 218 - 237, Pl. XI. 
| Lectures on the Comparative Anatomy and Physiology of the Invertebrate Animals, 
p. 252, 1843. 
§ Bericht über die Verhandlungen der naturforschenden Gesellschaft in Basel, V. pp. 
191-198, 1843. (Communicated Mar. 2, 1842.) 
|| I have not been able to see Erdl's paper on Demodex in the Bulletin of the Academy 
of Munich, 1843. 
T ‘Researches into the Structure and Development of a newly discovered Parasitic Ani- 
malcule of the Human Skin, — the Entozoon Jolliculorwn." Philosph. Trans. Royal Soc. 
