the Atiaclcs of Insects and Fungi. 
249 
described under the head of " Fruit Crops," becatise it is con- 
sidered that they would not be practically useful in orchards, on 
account of the impossibility of covering large trees sufficiently 
with spray, and getting at all aides of the trees, during their 
necessarily rapid transit. These horse machines, it is obvious 
also, could not work in plantations with standards and fruit- 
bushes growing together. They may be used, with many modi- 
fications and alterations, in plantations of fruit-bushes set alone, 
but not where there are large trees requiring to be sprayed 
Fig. 22.— Pump fitted to garden engine. 
individually for some minutes. For these, hand-pump machines 
are essential. 
There are just a few more remedies to be noticed under this 
head. One of these is lime used as a wash for the bodies and 
larger limbs of fruit-trees, put on thickly and freshly slaked in 
the autumn. If this is thoroughly well worked into the bark with 
a stiff brush, many insects in various forms will be dislodged, 
and the lime adhering to the bark may in a degree prevent some 
insects from ascending. Lime-wash also removes the green 
lichenous growths on the stems and limbs of fruit-trees, which 
serve as a cover for many pests and affect the health of the 
trees. When fruit-trees, particularly apple-trees, have mosses 
and lichens upon their branches, harbouring insects in the egg, 
larval, pupal, and imago form, powdered lime should be thrown 
VOL. II. T. s. — 6 S 
