14 BULLETIN OF THE 



One finds it impossible to place any confidence in Wilson's account of 

 the excessive complication of structure of the parasite. He describes 

 the head as furnished with a pair of eyes, palpi, labrum (1), eight pairs 

 of tentacles, and four to ten pairs of maxillse ! He is disposed to remove 

 the creature altogether from the Arachnida and put it in close relation 

 with the Annelides or the lower Crustacea. Waiving the question of its 

 exact systematic position, he gives it a provisional name, Entozoon folli- 

 culorum* The first notice of the presence of Demodex in other animals 

 than man was a communication read by Mr. Tulk before the Micro- 

 scopical Society of London, December 20, 184r3.t He obtained speci- 

 mens from Mr. Topping, a preparer of microscopic objects, who found 

 them in the contents of pustules on a mangy dog. The parasites were 

 very abundant, sometimes thirty or forty in a single drop of pus. The 

 dog was spoken of as " a perfect mass of disease." 



In 1844 the animal received a name for the fifth time, when Gervais, 

 translating a part of Dr. Simon's paper for the " Histoire Naturelle des 

 Apteres" pi'oposed the name Sivionea foUiculoriim.X 



The next observer to turn his attention to this subject was Gruby,§ 

 who found the Demodex in men and dogs, causing in the latter a serious 

 mangy affection of the skin. He noticed that the parasites spread in 

 a circle from follicle to follicle, and believed that the human and canine 

 forms were the same species, and capable of transmission from one host 

 to the other. 



In 1845 Dr. Gros announced the discovery of Demodex in the snout 

 of the dog, fox, horse, ox, etc. || 



At a meeting of the " Freunde der Naturwissenschaften " in Vienna, 

 !March 26, 1847, Dr. Carl Wedl presented a paper on the anatomy and 

 development of Demodex.^ 



Kiichenmeistcr, in his work on the parasites of the human body, 1855, 



London, 1844, Pt. L pp. 305-319, PI. XV. -XVII. (Read Mar. 30, 1843. Abstract in 

 Ann. and Mag. Nat. Hist. XII. p. 222, 1843, ami in Proc. Royal Soc. V. p. 495, 1843-44.) 



* In his " Diseases of the Skin," 2d ed., 1847, Wilson gives the parasite a new generic 

 name, Slealozoon. 



+ An .abstract of this communication is given in "Tlie Annals and Magazine of Natural 

 History," XIII. p. 7.''), 1844. 



* Hist. Nat des Insectes, Apteres, III. pp. 153, 282, 1844. 



§ " Recherches sur les animalcules parasites des follicules sebacoa et des follicules des 

 poils de la peau de riiomme et du chicn." Coniptes Rendus hebdomadaires des Seances 

 de I'Acadeniie des Sciences, XX. pp. .')69-572, 1845. 



II Bulletin de la Soiiete Iinperiale des Natunilistes dc Moscou, XVIII. p. 415, 1845. 



\ " Ueber die Haarsackuiilbe {Acarm folliculormn)." Haidinger's "Berichte." Bd. 

 ;i. pp. 272-277, 1847. 



