DIRECT INJURIES CAUSED BY INSECTS. 137 



other quadrupeds ; but I suspect have no notion that 

 there is a species appropriated to man. The existence, 

 indeed, of this species seems to have been overlooked 

 by entomologists (though it stands in Gmelin's edition 

 of the Si/stema Naturm^^ upon the authority of the 

 younger Linne,) till Humboldt and Bonpland men- 

 tioned it again. Speaking of the low regions of the 

 torrid zone, where the 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 Ilominis^ Avhich de- 

 posits its eggs in the skin of man, causing there painful 

 tumours''. Gmelin says that it remains beneath the 

 skin of the abdomen six months, penetrating deeperj 

 if it be disturbed, and becoming so dangerous as some- 

 times to occasion death. The imaffo he describes as 

 being of a brown colour, and about the size of the com- 

 mon 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 ovi- 

 posit in the jaw of a woman, and the bots produced 

 from the eggs finally caused her death ". — Other flies 

 also of various kinds thus peneti'ate into us, either 

 preying upon our flesh, or getting into our intestines. 

 Leeuwenhoek mentions the case of a woman whose 

 leg had been enlarging witli 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 



^ From Pallas N. Nurd. Beytr. i. 157. 

 ' Essai sur la Geograph. des Plantes, 136. 

 * Clark In Linn. Trans, in. 323, note. 



