56 
HOP. 
—that is, winged Aphis—appeared. Also, there does not appear to 
me to be any reason to doubt that the Hop and Damson-Hop Aphis 
are merely slight varieties of one species, a remark which scarcely 
occupies a couple of lines, but which required constant examination of 
parallel condition of the two sorts from March to September, and 
which (if correct) lies at the root of the most important measures for 
prevention, save those above mentioned. 
Amongst measures of remedy, dressings with paraffin in any dry 
material, by which it can be spread on the hills in spring, have been 
shown to be useful, and so has the addition of quassia to the washings ; 
whilst amongst methods of washing, the application of the steam- 
power to this purpose opens up a possibility of carrying these opera¬ 
tions on with a greater rapidity and less cost, of which the further 
proofs will be looked for with interest. 
I should also add my thanks to the many correspondents through 
whose courtesy and likewise painstaking search I have been furnished 
with observations and specimens from which the above notes have 
mainly been taken. 
Fever Fly.* Dilophus vulgaris , Meigen ; D. febrilis, Linn. 
Dilophus vulgaris. 
Female Fly, magnified and nat. size, flying round Hop-cones. 
At the beginning of April specimens of larvse were forwarded to 
me from Mr. Faunce de Laune, of Sharsted Court, Sittingbourne, with 
the information that they were found in a piece of Hop-root sent 
accompanying, and appeared to be feeding on it, and that the same 
kind of grubs were then rather numerous in the Hop-liills. The piece 
of Hop was partly decayed, and, on cleaning it to gain a sight of the 
* As this Fly appears to be without an English name, I have retained the 
original one given by Linmeus from the Fly being supposed to occur in the rooms 
of fever patients, 
