INDIRECT INJURIES CAUSED BY INSECTS. 165 



To avoid this pest it is obliged to leave the cover of the 

 woods in full day, and seek the plains : hence the hun- 

 ters say, that of three litters which a hare produces 

 in a year, the first dies by the cold, the second by gnats, 

 and only the third escapes and comes to maturity a . — We 

 learn from the ingenious Mr. Clark, that the American 

 rabbit and hare are infested by the largest species of 

 CEstrus 5 yet discovered; and our domestic rabbits some- 

 times swarm with the bed-bug. This was the case with 

 some kept by two young gentlemen at my house last 

 summer to such a degree, that I found it necessary to 

 have them killed. 



Nor are the inhabitants of the waters sheltered by their 

 peculiar element from these universal assailants. The 

 larvae of Dytisci fixing themselves by their suctorious 

 mandibles to the body ofjish, doubtless destroy an infi- 

 nite number of the young fry of our ponds. Some spe- 

 cies of salmon (Salmo Fario, L.) are the food of an ani- 

 mal which Linne has arranged under Pediculus ; and 

 probably many others of the finny tribes may, like the 

 birds, have their peculiar parasites. Even shell-jish do 

 not escape, for the Nymphon grossipes, Latr. enters the 

 shell of the muscle and devours its inhabitant. 



I am, &c. 



a De Geer, ii. 83. 



b Considered by Mr. Clark as a new genus, which he has named 

 Cuterebra, and of which he has described three species. Essay on 

 the Bots of Horses, $c. p. 63. t. 2.f. 24-29. 



