22 
importance cannot be over-estimated. As far as my 
own observations go I think it is very likely that we shall 
find it correct. For some years I have inclined to think 
attack with various crops especially followed on rough 
weeding and thinning, in which the smell from the 
bruised plants and those left perishing on the land 
spread in the air ; but I had not, until receipt of Prof. 
Lintner’s paper, the key to the reason. 
If we could have experiments as to effect of various 
strongly scented dressings including in these both such 
as are known to be unattractive,—as various forms of tar, 
or paraffin, kerosine, petroleum, &c., also of dressings 
of gas lime or mixtures of sulphur,—and on the other 
hand, of effects of special animal manures, some of which 
are either attractive or at least have had their application 
followed by appearance of “ Fly,” we should gain very 
beneficial information, and also it would be worth while 
to note whether any increased attack could be definitely 
shown to follow the operation of thinning. 
Analysis of the constituents of plants to which different 
dressings have been applied would also (in connection 
with absence or presence of attack) be very serviceable, 
as well as notes of the effect of different applications on 
rapidity of growth; and, Gentlemen, nowhere better 
than in your hands could these points be worked out 
scientifically, and the results given in information for 
practical service which would be highly beneficial to 
us all. 
I am indebted to the courteous liberality of Messrs. 
Blackie & Son, Glasgow, for the use of the illustrations, 
which are from the pencil of John Curtis. 
WEST, NEWMAN AND CO., PRINTERS, HATTON GARDEN, LONDON, E.C. 
