THE NEW FORESTRY. 203 



growing at the collar of the affected trees and away from 

 them as well. Hartig gives a very correct description of this 

 fungus, and also of Trametes radici-perda> which he describes 

 as being, if anything, worse than the Agaricus, affecting the 

 trees in a similar way. The only preventive he suggests is 

 digging a deep trench round the affected spots to prevent the 

 fungus extending, which it can only do through the soil, but 

 in our own case that is impracticable, as the stools are every- 

 where in autumn, and the surprising thing is that so few trees 

 comparatively are attacked. 



Reverting to the beetle plagues mentioned, we 'have 

 come to think that some trees are more predisposed to their 

 attacks than others. It is certain, at all events, that the pine 

 beetle and fir weevil are rarely or never absent from pine 

 woods, and are often tolerably abundant where no damage 

 to anything approaching the extent described by Miss E. A. 

 Omerod is ever seen. The only preventive measures sug- 

 gested by experts in these matters is the removal of all debris 

 in the shape of decaying stumps and branches from the woods, 

 as the insects shelter and breed among these in winter and 

 spring and come out to feed on the trees in summer. 



COMMON SPRUCE FIR, SILVER FIR, AND OTHERS. With 

 these are included the later introduced species like the Douglas 

 fir, Abies noblis, and others named in Chapter VII. The 

 common spruce and silver fir suffer more from diseases and 

 insects than any of the other spruces, the same beetles, weevils, 

 and fungus attacking them that attack the Scotch fir. The 

 spruce gall aphis crimps the shoots of weak trees but does 

 not hinder trunk development seriously. What seems to hurt 

 all the abies family most and predispose them to disease are 

 cold keen winds. Western gales blow the trees down, but 

 keen, cutting east winds kill the trees eventually wherever 

 they are exposed, and none are more sensitive than the 

 common spruce. Planted in gullies, or in plantations well 

 sheltered at their margins, the trees grow fast and are not 

 seriously affected by disease unless the soil is very thin and 

 dry, and then they make little headway anywhere. Removal 

 of the debris from the wood is the only preventive of the 

 ravages of insects. 



THE LARCH. Among forest trees no disease has caused 

 so much trouble and disappointment to planters as that 

 commonly known as the " larch disease," viz., ulcer or cancerous 

 blister. This disease attacks the tree in all soils and situa- 

 tions, and it is doubtful if any of the explanations offered 



