328 Proceedings of Royal Society of Edinburgh. [sess. 
circumference of the wounds widens from outside inwards, the 
innermost part being the widest, doubtless from the moving about 
of the proboscis in the feeding region. In healthy pines little 
bead-like drops of resin issue from the punctures, and when, after 
more than a year’s time, I have peeled the bark from a still living 
pine which had held feeding but not egg-laying notatus for a 
month, the old feeding-places in the cambial region were plainly 
marked out as tiny red-brown patches. The punctures may be 
dangerous in another way, as forming convenient entrance holes 
for the spores of injurious fungi. 
The larva tunnels in the bark and between the bark and wood, 
and where the bark may be thin the outermost part of the 
youngest wood may be also gnawed away. 
The favourite breeding places are young pines from three or four 
to eight years of age, but trees in the pole stage are also frequented. 
The favourite host plant is the Scots pine ( Pinus sylvestris), but 
in Britain I have also obtained notatus from Austrian pine ( Pinus 
Austriaca ), and Weymouth pine ( Pinus strobus). There are 
Continental records of attack on spruce and larch, but this is 
exceptional. 
Whether the beetles attack and breed in healthy trees is a much- 
vexed question. In the world of timber-infesting beetles we meet 
with various demands as regards quality of food. Some are 
dainty, asking for a better quality of material, some are easier to 
satisfy, while some are not at all particular. Thus I find Bos- 
trichus typographies dainty, while Hylesinus piniperda will practi- 
cally put up with anything. 
How in deciding this question for notatus, I have no hesitation 
in saying that it asks for a certain quality. While in old trees 
the weakly and sickly will be chosen, the thinned branches of 
perfectly sound trees and any part of a healthy young plant can 
be used for breeding. The beetles bred quite willingly in the 
young plants I offered them, these being always freshly dug from 
nursery or plantation, and apart from a slight ‘ checking ’ that 
would follow the transplanting, there could be no possible sus- 
picion of their vigour. 
The female after copulation lays her eggs in holes in the bark. 
If pines in the pole stage be chosen, then as several eggs may 
