16 
in neglected spots, as the Wild Oat, the Soft Brome- 
grass, beside the Bough Cocksfoot, and others. Several 
of the insects injurious to the Hop also frequent the 
Nettle, which is nearly allied to it botanically, and the 
small Ermine Moth infests the Hawthorn with its webs 
full of caterpillars as well as the Apple. 
Kemoval of weeds, or an unnecessary amount of useless 
plants which feed or attract the crop-insects, is desirable 
in itself, and it also acts well by diminishing the un¬ 
natural aggregation of special kinds of vegetation, which 
is one of the causes of the unnatural aggregation of 
insects injurious to us agriculturally. Where plants are 
scattered over the face of the country, the insect-feeders 
on them are necessarily fewer, and are subject to many 
more circumstances tending to diminish their numbers 
than v/here, as amongst growing crops, there is every 
appliance for their nurture, food, protection, and the 
support of suecessive broods on the same spot, or in the 
same neighbourhood, year after year. We cannot avoid 
this, hut we can avoid allowing our fields, the edges of 
woodlands, or Avaste patches being full of the kinds of 
AA^eeds or AAuld plants calculated to increase the evil. We 
liaA^e destroyed the natural balance by the amount Ave 
groAv of food-crops, and, as might he expected, Ave have 
often an increase in the amount of the insect-feeders ; hut 
as these depend on many circumstances, states of AA^eather 
amongst others, for their full development, the amount 
of attack cannot alAA^ays he calculated on, and AA^e need 
to hold the remedies in our hands to apply as called for, 
or else Ave may suffer severely. 
For this reason the indiscriminate encouragement of 
insectivorous birds is not so entirely desirable as it is 
sometimes thought. The flocks that appear Avhen there 
are special attacks should by all means be protected, and 
their very presence taken as a sign that there is some¬ 
thing underground needing attention. Such are Hocks of 
Books tearing up the grass infested by grubs of various 
kinds. Sea Gulls following the plough. Titmice destroying 
Aphides, and other instances could be multiplied ; also a 
