0 
PINE BEETLE. 
115 
“ In the beginning of April of this year, in the Upper Ward of 
Lanarkshire, on a south-west slope, at an elevation of some 800 feet, 
I found that several Larches, which had been felled during last winter, 
were attacked by large numbers of this insect. In its company I also 
found Hylastes palliatus , but by far the greater number of galleries 
were the work of Hylesinus piniperda. Daring the past three months 
these trees have been kept under close observation, with the result 
that I find one or two particulars in which the attack of this insect on 
the Larch differs from its mode of attacking the Scots Pine. 
“ The greater abundance of fluid resinous matter in the Larch, as 
compared with the Scots Pine, seems to have considerably interfered 
with the work of forming galleries. I noticed that all the trees lying 
in the wood were not attacked, but only those at one side, where they 
were within the shade cast by a dense wood of Pines situated to the 
south. This I believe to be due to the fact that the cambial activity 
and formation of resinous solutions were retarded in these trees owing 
to their not being directly reached by the sun’s rays; whereas the 
cambium and cortex of those trees fully exposed to the sun were so 
saturated with resin as to be safe from attack. Even in some of the 
