DIRECT INJURIES CAUSED BY INSECTS. 87 



avoid them is impossible. At last, subdued by pain and 

 fatigue, lie throws himself in despair with his face to the 

 earth, and half suffocated in his blanket groans away a few 

 hours of sleepless rest." We have one species {Stomoxys 

 calcitrans\ alluded to in a former letter, as so nearly resembling 

 the common house-fly, which, though its oral instruments are 

 to appearance not near so tremendous, is a much greater 

 torment than the horse-fly. This little pest, I speak feel- 

 ingly, incessantly interrupts our studies and comfort in 

 showery weather, making us even stamp like the cattle by 

 its attacks on our legs ; and, if we drive it away ever so 

 often, returning again and again to the charge. In Canada 

 they are infinitely worse. " I have sat down to write," says 

 Lambert (who, though he calls it the house-fly, is evidently 

 speaking of the Stomoxys), " and have been obliged to throw 

 away my pen in consequence of their irritating bite, which 

 has obliged me every moment to raise my hand to my eyes, 

 nose, mouth and ears in constant succession. When I could 

 no longer write, I began to read, and was always obliged to 

 keep one hand constantly on the move towards my head. 

 Sometimes in the course of a few minutes I would take half 

 a dozen of my tormentors from my lips, between w^hich I 

 caught them just as they perched." ^ 



The swallow-fly (^Craterina Hirundinis'^), whose natural 

 food is the bird after which it is named, has been known to 

 make its repast on the human species. One found its way 

 into a bed of the Rev. R. Sheppard, where it first, for several 

 nights, sorely annoyed a friend of his, and afterwards himself, 

 without their suspecting the culprit. After a close search, 

 however, it was discovered in the form of this fly, which, for- 

 saking the nest of the swallow, had by some chance taken its 

 station between the sheets, and thus glutted itself with the blood 

 of man. — In travelling between Edam and Purmerend in North 

 Holland (July 21. 1815), in an open vehicle, I was much 

 teased by another bird-fly (^Ornithomyia avicularia) (two 

 individuals of which I caught) alighting on my head, and in- 

 serting its rostrum into my flesh. — Mr. Sheppard remarks, 

 as a reason for this dereliction of their appropriate food, that 



1 Travels, &c. i. 126. 2 See Curtis's Brit. Ent. t. 122. 



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