1847.] The Hessian Fly. 207 



of 1841, which was accompanied bv a series of specimens of a 

 Cecidomyia, from the egg to the perfect fly, obtained by me, as 

 there described. 



That this statement and these specimens have escaped Dr. 

 Fitch's notice, is evident; a circumstance which I deeply regret, 

 as it obliges me thus publicly to call his attention to them, if I 

 have mistaken some new insect for the Cecidomyia destructor, I 

 must plead as an excuse, their accurate resemblance even under a 

 high magnifying power, to Mr. Le Sueur's beautifully accurate 

 drawings, accompanying Mr. Say's as accurate descriptions of the 

 fly, that " appears early in June, deposits its eggs, and dies." I 

 will now ask Dr. Fitch what fly was it that did appear early in 

 June, in such numbers, in this neighborhood, in the years 1S36, 

 '40, and '41? 



If Dr. Fitch will prove that the flies I so carefully watched for 

 so many years, whose larva feeds in the centre of the straw, as 

 seen by hundreds in this neighborhood, is " the fly he suspects it 

 to be," I will acknowledge my error as frankly as I now maintain 

 my difference of opinion. 



I do not, nor have I ever doubted the statements of gentlemen 

 so learned in the science of Entomology as Messrs. Heirick and 

 Dana; their assurance that they had seen the insect in hs different 

 states of egg, larva, pupa, and perfect fly, was sufficient to satisfy 

 me that it was so; I therefore, in all fairness, claim the same in- 

 dulgence from them and others, when I state that I saw, captured, 

 and glued to a piece of paper, a f!y, while in the act of deposit- 

 ing her eggs on a grain of wheat, so like the drawing made by 

 Le Sueur, of Say's Cecidomyia destructor, that it not only de- 

 ceived me, but all to w^hom I showed it. And that this fly and 

 eggs, 1 did present to the Academy of Natural Sciences, is beyond 

 question; and that subsequently I did procure larvse and pupee of 

 this species, in the centre of the straw, is equally beyond doubt, 

 as shown in the Journal of the Academy of Natural Sciences, 

 August number, page 66 — which straw, larvae and pupse, are now 

 in my possession. Again, I ask Dr. Fitch what is the name of 

 this fly? 



The concluding paragraph of the communication here referred 

 to, will show that my opinions have not altered since 1841: 

 " From this series of facts, it might be presumed that the history 

 of this interesting and destructive insect was decided; but the 

 statements of observers whose information and accuracy cannot 

 be questioned, prove discrepancies in its history, that can only be 

 reconciled by supposing that there are two species under observa- 

 tion. The species now presented, will agree with Mr. Say's 

 statement, that ' the fly appears early in June, lives but a short 

 time, deposits its eggs, and dies.' The remainder of Mr. Say's 



