6 
above statement, and says, “At that time I did not know that a 
yellow fly had deposited the eggs within the glume, which became 
maggots. Observing numbers of black flies on the ears of wheat, I 
believed they had been the produce of the caterpillar. I have this 
season, however, observed the yellow fly (described by Rev. W. 
Kirby) deposit its eggs in the wheat-ear,” etc. I notice this more 
particularly, because the farmers in this vicinity, with scarcely an 
exception, have fallen into the same error, and to this day suppose 
a small black fly, of the family Muscid@, which occurs abundantly 
in wheat-fields, to be the real wheat-fly. 
Mr. Patrick Shirreff, of East- Lothian, gives, in the same volume 
of Loudon’s Magazine, pages 448 - 451, an excellent and very 
accurate summary of the habits and transformations of the same 
insect, the result chiefly of his own observations. For a concise 
account, this is not surpassed by any that has fallen under my notice. 
Still more recently, this subject has been investigated by Prof. 
Henslow, from whom a communication appears in the Journal of 
the Royal Agricultural Society of England, vol. ii. p. 26; and in 
the same journal for the present year (vol. vi. p. 131. plate M.) an 
admirable production is inserted from the pen and graver of that 
accomplished naturalist, John Curtis, F.L.S., giving much more 
accurate and precise descriptions and delineations of the wheat-fly, 
in the different stages of its existence, than any that had previously 
appeared. To it I am particularly indebted for such characters as 
enable me to say without a doubt, that the clear-winged wheat-fly 
of America is identical with the English Cectdomyia tritict. 
In closing this summary of the notices of the wheat-fly abroad, I 
would allude to what has occurred to me as perhaps true in the 
history of this insect, to wit, that it has somewhat regular periods 
of recurring in such numbers as to become a pest to the agri- 
culturist. Thus, it would appear from Mr. Gullet’s account, that it 
had been common for a few years previous to 1771. After an in- 
terval of twenty-five years, it is again observed plentifully for three 
or four years, and in different districts, by Messrs. Kirby, Markwick 
and Long. Again it ceases to elicit attention, until a period but a 
little longer elapses, when, in 1828 and the following years, it forces 
itself once more and still more prominently into notice. All that I 
design, is, to direct attention to this point : the facts are as yet too 
few and too vague to justify anything more than a suggestion. The 
