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 Willkommii. 

 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 



