136 DIRECT INJURIES CAUSED BY INSECTS. 



to have been voided from the nostrils of a young man 

 long afflicted with dreadful pains in his head a . But 

 the most extraordinary account with respect to lepido- 

 pterous larvae (unless he has mistaken his insects) is given 

 by Azara, the Spanish traveller before quoted ; who says 

 that in South America there is a large brown moth, which 

 deposits its young in a kind of saliva upon the flesh of 

 persons who sleep naked; these introduce themselves 

 under the skin without being perceived, where they oc- 

 casion swelling attended byinflammation and violent pain. 

 When the natives discover it, they squeeze out the larvae, 

 which usually amount to five or six b . 



But amongst all the orders, none is more fruitful in 

 devourers of man than \heDiptera. The Gad-fly (CEs- 

 trus, L.) you have, doubtless, often heard of, and how 

 sorely it annoys our cattle and other quadrupeds ; but 

 I suspect have no notion that there is a species appro- 

 priated to man. The existence, indeed, of this species 

 seems to have been overlooked by entomologists (though 

 it stands in Gmelin's edition of the Systema Natures c , 

 upon the authority of the younger Linne,) till Humboldt 

 and Bonpland mentioned 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 (Estrus Hominis, which 

 deposits its eggs in the skin of man, causing there pain- 



a Fulvius Angelinas et Vincentius Alsarius De verme admirando per 

 nares egresso. Raven nae 1610. 



b Azara, 217. I cannot help suspecting this to be synonymous with 

 the (Estrus Hominis next mentioned. 



c From Pallas N. Nord. Beytr. i. 157. 



