Mr, Marsuam’s further Obfervations on the Wheat Infect. 228 
of the flower, until the feed was ripe ; and the refult of their unre- 
mitted endeavours, with a few of my own obfervations, I now lay 
before you, requefting, that if you think them worthy their atten- 
tion, you will prefent them to our valuable Society; for fuchI ~ 
think it may be truly ftyled, fince the opinion of the Public has fo 
fully ftamped its confequence. 
Mr. Markwick, in a letter to me dated the 17th July 1797, 
{tates as follows :—‘* On the 12th of this month I firft difcovered 
fome of the little flies (which I fend you inclofed) fitting between 
the hufks or clefts of the ears of wheat: the next day they ap- 
peared to me more abundant; and then, for the firft time, I found a 
few of the {mall yellow larvae, which infefted the wheat in the 
year 1795, fitting clofe to the ftamina, exactly as they are repre- 
fented in the 3d vol. of the Liznean Tranfaélions, page 251. Tab. 22, 
fig: 10. a; fince that time I have found the larve in much greater 
abundance, and the fly is alfo to be feen, though I think not in 
fuch great numbers. The other infects which I have difcovered 
on the wheat, are the Thrips phy/apus, in its larva and perfec ftate, 
as in the year 17953° and fome of the ears were infefted with the 
plant loufe (4phis) called here the Dolphin.” On the 25th of 
July, I received alfo a letter from Mr. Kirby, that contained fome 
valuable hints, which induced me to fend a copy of it to Mr. Mark- 
wick ; and on the 17th of September I was favoured with the fol- 
lowing letter from that gentleman :— 
“| want words to exprefs the pleafure I received from your laft let- 
ter, as well as from your obliging communication of that of your very 
ingenious and learned friend Mr. Kirby, and fhould have acknow- 
ledged the obligation fooner, but waited until the end of harveft, 
with the ill-founded hope of having fomething to communicate re- 
lative to our little infe&t worthy of your notice; for I am forry to fay, 
Vor. IV. Gg that 
