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 Zlirich 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 Poli/stoma, 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 Muller's Archiv for 1842. t 

 It was iu 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 zoological 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,| without making any new observations, fixed the position of the 

 animal more precisely, making it the type of a new genus, Demodex, and 

 during the same year Miescher § published a description of it under the 

 name Platypus macrogaster. \\ 



Erasmus Wilson,ir also in 1843, made extensive studies 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 the ear. He put it among the Tanligrades, 

 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 Haarsacken des Menschen lebende Milbe.' 

 Arch. f. Aiiat. Physiol, u. Wissensch. Med. 1842, pp. 218-2.37, PI. XI. 



\ Lectures on the Comparative Anatomy and Physiology of the Invertebrate Animals, 

 p. 2.52, 1843. 



§ Bericlit iiber die Verhandlungen der natnrforschenden Gesellschaft in Basel, V. pp. 

 191-198, 1843. (Communicated M.ar. 2, 1842.) 



II I have not been able to see Enll's paper on Demodex in the Bulletin of the Academy 

 of Munich, 1843. 



% " Researches into the Structure and Development of a newly discovered Parasitic Ani- 

 malcule of the Human Skin, —the Entozoon foUiailonim." Philosph. Trans. Royal Soc. 



