Some Account of the Hessian Fly, 



227 



rule without an exception ;" but that it should be produced 

 by the tree itself. It did not strike him, that the " particular 

 insects " might cause the peculiarities of the gall, nor that the 

 " particular insects " might choose particular trees in which to 

 deposit their eggs. The insects found in fruits, he also sup- 

 poses to be generated by virtue of the tree itself, and without 

 any pre-communication with the perfect insect. In support 

 of this doctrine he supposes trees to be endowed with sens- 

 ation, and brings many revered names to . assist him in his 

 need, among whom he cites Aristotle, Plato, and Pythagoras. 



T. L. H. 



Art. VI. 



Sir, 



Some Account of the Hessian Fly, By the Reverend 

 William Kibby, M. A. F.R. and L.S. 



No departments of natural history are more generally in- 

 teresting than those which connect it with agriculture. I need 

 not, therefore, apologise for making known to the public, 

 through the medium of your useful Magazine, the name and 

 characters of an insect, which, under the appellation of the 

 Hessian fly, has done as much damage to the crops of wheat 

 in North America, and created as much alarm in this country, 

 lest it should be imported, as any depredator of its class ever 

 did.* Having been long anxious to ascertain what the insect 

 was, that had attained to such celebrity for the injuries it was 

 the author of, I applied to a friend connected with America to 

 give what information he could procure, but without success ; 

 till, very recently, I met with a paper of Mr. Say's upon this 

 very subject, inserted in the Journal of the Academy of Natural 

 Sciences of Philadelphia for the year 1817. 



I had, in the Linnean Trans- 

 actions, long ago, under the 

 name of TIpula ^ritici [fig, 91. 

 «), given an account of a little 

 orange-coloured gnat, which I 

 conceived to be injurious to the 

 wheat crops of this country, 

 by causing the inanition of the 

 grain wherever it laid an egg f , 

 which was within the glumes 

 of the florets. This gnat, in 

 the modern system, belongs 



* See Introduction to Entomology, first edition, p. 52. 168. 

 t Linn. Trans., iii. 242—245. iv. 224 — 230. v. 96—110. 



