GENERAL SUMMARY 183 
The bulky literature of the larch canker is almost entirely 
the product of predispositionists. “About ten papers or 
notes have been published in English on larch canker for 
every one on heart-rot or the honey fungus, though the 
latter diseases are very nearly as destructive as canker, and 
the honey fungus, when the catholicity of its taste in forest 
trees is taken into account, is probably by far the most 
destructive of all forest pests. The explanation of this 
anomaly appears to be that many foresters will dilate on 
the general sylvicultural conditions which make for the health 
or sickness of a tree, whereas few are prepared to discuss 
the more directly pathological factors which control attack 
by a fungus which is just as prepared to parasitize healthy 
trees as sickly ones. We will follow this bent and consider 
first the general sylvicultural requirements of the tree. 
In the literature of larch culture with relation to canker, 
great stress has been laid on the alpine habit of the tree, 
which is repeatedly dragged in to explain failures of cultiva- 
tion at lower elevations. Cieslar (1904), in a reasoned paper, 
shows that too much importance has been attached to this 
feature. In the Alps the present natural distribution of 
the tree is confined to high altitudes, but in Silesia it comes 
down to 1,000 ft., and near Sokol it grows naturally and 
healthily, with silver fir, oak, &c., at an altitude of 600 to 
800 ft. Probably in the lowlands between the Carpathians 
and Russian Poland the larch has only been destroyed by 
cultivation, and in earlier days the alpine nature of its 
distribution may have been much less clearly marked. 
There are, also, many lowland places where cultivated larch 
grows extremely well, and in many parts of its natural home 
canker is very prevalent. 
Be this as it may, the larch has certain alpine charac- 
teristics which must be taken into account in cultivation. 
Chief of these are its faculty for bearing extreme cold in the 
winter and its susceptibility to spring frosts. Alpine plants 
have to contend with a short growing season and waste no 
time in getting about summer work as soon as the snows 
melt. On this account the bursting of the buds is generally 
