DIRECT INJURIES CAUSED BY INSECTS. 109 



air is filled with those myriads of mosquitos which render 

 uninhabitable a great and beautiful portion of the globe, 

 they observe that to these may be joined the CEstrus Ho- 

 minis, which deposits its eggs in the skin of man, causing 

 there painful tumours.^ Gmelin says that it remains be- 

 neath the skin of the abdomen six months, penetrating 

 deeper, if it be disturbed, and becoming so dangerous as 

 sometimes to occasion death. The imago he describes as 

 being of a brown colour, and about the size of the common 

 house-fly; so that it is a small species compared with the 

 rest of the genus.^ Even the gad-fly of the ox, leaving its 

 proper food, has been known to oviposit in the jaw of a 

 woman, and the bots produced from the eggs finally caused 

 her death.^ Other flies also of various kinds thus penetrate 

 into us, either preying upon our flesh, or getting into our 

 intestines. Leeuwenhoek mentions the case of a woman 

 whose leg had been enlarging with glandular bodies for some 

 years. Her surgeon gave him one that he had cut from it, 

 in which were many small maggots : these he fed with flesh 

 till they assumed the pupa, when they produced a fly as 

 large as the flesh-fly.^ — A patient of Dr. Reeve of Norwich, 

 after suflering for some time great pain, was at last relieved 

 by voiding a considerable number of maggots, which agree 

 precisely with those described by De Geer as the larvas of 

 his Musca domestica minor {Anihomyia canicularis Meig.), a 

 fly which he speaks of as very common in apartments.^ — In 

 Paraguay the flesh-flies are said to be uncommonly numerous 

 and noxious. Azara relates^ that, after a storm, when the 

 heat was excessive, he was assailed by such an army of them, 

 that in less than half an hour his clothes were quite white with 



1 Essai sur la Geograph. des Plantes, 136. 



2 For an investigation of the question, whether man is attacked by a distinct 

 species of (Estrus, see a report on the statements of MM. Roulin, Howship, 

 Say, Guerin, &c., made to VAcademie des Sciences, 1833, by MM. Isidore 

 GeofFry Saint Hilaire, and Dumeril (copied in Ann. Soc. Ent. de France, ii. 

 518.), who, on the whole, though with some hesitation, pronounce for the affirm- 

 ative. Yet most of the facts passed in review seem rather to support the idea 

 that species of (Estrus, whose proper abode is in other animals, occasionally attack 

 man. 



3 Clark in Linn. Trans, iii. 323. note. 



4 Leeuw. Epist. Oct. 17. 1687, ubi supra. De Geer, vi. 26, 27. 

 ^ Edinh. Med. and Surg. Journ. 6 p. 216. 



