184 



mal existed there in abundance in the year 1834, and have 

 good reason to suppose that it has injured wheat there for a 

 century or more. Mr. James D. Dana, whom you doubtless 

 know, had frequently assisted me in my examinations of the 

 Hessian Fly and parasites, and of their habits and metamorpho- 

 ses ; and Avhen he went to Europe, in 1833, in the Delaware, I 

 gave him a card containing a drawing and description of the 

 animal, with directions and incpiiries to be followed and made. 

 Moreover, he was at that time personally acquainted with the 

 Hessian Fly, and could, I think, identify it certainly. On the 

 island of Mahon, and also near Naples, he found the identical 

 insect in wheat stubble ; he saw the perfect insects, the pupaa 

 and the larva?. He sent me in the seal of a letter three or 

 more specimens of the imago, and when he returned he brought 

 several o'lass tumblers containino- the culms of wheat witk the 

 pupae upon them. After the best comparison I could make I 

 thought the insect identical with the Hessian Fly of this coun- 

 try. This was also his opinion. It is truly astonishing that 

 their naturalists have not found it out. I fear they have al- 

 ready, for Dr. Hammerschmidt, of Vienna, published three or 

 four years since a pamphlet on a two-winged insect which in- 

 jures wheat in Hungary. 



Kirby's Tlpula tritici is doubtless a congener of the C. de- 

 structor^ and exists in this country, at least in New Haven, in 

 abundance. I cannot find out, however, that it injures the 

 wheat here, which induces me to suspect that it is a different, 

 though closely alhed species. Kirby's description is quite too 

 imperfect. 



Page 47 has many errors. Line 3, "eight" might as well be 

 fifty or a hundred, or perhaps a larger number. The assertion 

 in the next sentence has always surprised me, for it seems as 

 if he states what he had actually seen. But the statement is 

 certainly untrue, and, I may say, the fact is impossible. The 

 oviduct is so short and so soft that it would be impossible to 

 thrust the egg a twentieth of an inch between the culm and the 



