128 DIRECT INJURIES CAUSED BV INSECTS. 



mands of hunger or the stimulus of revenge. There is 

 however a third class of insect annoyers, as I observed 

 at the beginning of this letter, which, though they nei- 

 ther make us their food, nor attack us under the im- 

 pulse of fear or revenge, incommode us extremely in 

 other ways. These must now be detailed to you. 



How extremely unpleasant is the sensation which that 

 very minute creature, Thrips physapus, L., excites in 

 sultry weather, merely by creeping over our skin ! I 

 have sometimes found this almost intolerable. A simi- 

 lar torment, reckoned by Ulloa a kind of Mosquito, in- 

 fests the inhabitants of Carthagena in South America. 

 They are there called Mantas blancas, and creeping be- 

 tween the threads of the gauze curtains that keep off the 

 former pest, though they do not bite, occasion an itch- 

 ing that is dreadfully tormenting 3 . But these are no- 

 thing compared with the teasing attacks of the Simidiwn 

 repta?is, Latr., which, as Linne informs us, who mis- 

 named it a Culex, is so incredibly numerous in Lapland, 

 as entirely to cover a man's body, turning a white dress 

 into a black one, occupying the whole atmosphere, fillino- 

 the mouth, nostrils, eyes, and ears of travellers, and thus 

 preventing respiration, and almost choking them. These 

 little animals, he says, do not bite, but torture incessant- 

 ly by their titillation b . — In New South Wales a small 

 ant was observed by Sir Joseph Banks, inhabiting the 

 roots of a plant, which when disturbed rushed out by 

 myriads, and running over the uncovered parts of the 



a Ulloa, i. 64: Probably the Cafafi, a white fly noticed by Hum- 

 boldt, is synonymous with this of Ulloa, which could only be pre- 

 vented from creeping between the threads of the curtains by keep- 

 ing them wet. Personal Narrative, E. T. v. 10?. 

 • " Lack. Lapp. i. 208, 209. FL Lapp. 382, 383. It appears how- 

 ever, from other authors, that. they do bite. 



