AMONG THE PINES AND FIRS 227 
summer, and back again from late summer into 
the winter state of rest, it had to encounter the 
different conditions of a well-marked spring and 
autumn. But these conditions were, unfortunately, 
just those which favoured the growth and spread 
of a very destructive form of cankerous disease 
of the stem peculiar to the larch, due to a beauti- 
ful grey and orange fungus, Peziza Willkommit. 
This parasite occurs in the Alps also, it is true; 
but the sudden change from winter to summer 
and then back again to winter, combined with the 
greater dryness of the climate, prevents the Peziza 
from there ripening and scattering its myriad 
spores, while at the same time better enabling 
the larch to withstand attacks. The milder and 
more humid climate of Britain, the formation of 
large pure plantations, and no doubt also a con- 
stitutional vegetative power perhaps below par 
as compared with the natural vigour developed 
in its alpine home, in consequence of being 
planted on soils and in situations not really suit- 
able for it, have enabled this disease to obtain a 
very firm footing in Britain, and to become an 
epidemic scourge to the larch-grower. Many 
plantations become so badly affected with canker 
