INDIRECT INJURIES CAUSED BY INSECTS. 89 



rabbit, 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 hunters 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 3 yet discovered ; and our domestic rabbits sometimes 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 wafers sheltered by their peculiar element 

 from these universal assailants. The larvae of Dytisci, fixing themselves 

 by their suctorious mandibles to the body of fish, doubtless destroy an 

 infinite number of the young fry of our ponds. Some species of salmon 

 (Salmo fario L.) are the food of an animal which Linne has arranged 

 under Pediculus ; and probably many others of the finny tribes may, like 

 the birds, have their peculiar parasites. Even shell-fish do not escape, for 

 the Nymphon grossipes enters the shell of the muscle and devours its 

 inhabitant. I am, &c. 



1 De Geer, ii. 83. 



a 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. 



