166 INDIRECT INJURIES CAUSED BY INSECTS. 



do not escape their attack. The hare in Lapland is 

 more tormented by the gnats than any other quadruped. 

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

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

 ers 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 1 . We 

 learn from the ingenious Mr. Clark, that the American 

 rabbit and hare are infested by the largest species of 

 CEstrus b 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 ofjfish, 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 shellfish do 

 not escape, for the Nymphon grossipes 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 Sots of Horses, $c. p. 63. t, 2.f. 24-29. 



