Peziza Wilkommii. 17 



equally apparent, showing that the effects 

 are the same whether it arises from drought or 

 excessive moisture. This, however, is not the 

 only cause. The larch throws out its shoots 

 of tender green early in the season, and the 

 late frosts are apt to injure these and 

 disorganise the plant. Again, we find it in 

 overcrowded plantations, where thinning 

 has not taken place, and where three feet 

 planting has been adopted ; there is no light, 

 no air, the bark remains moist and becomes 

 a fit habitation for the spores of the parasitic 

 fungus known as the Peziza Wilkommii. 

 These spores are always more or less floating 

 about, and fall in due course upon the young 

 tender and Hving bark of the larch trees. 

 Finding the moisture and the dull light favour- 

 able to germination they germinate, throw 

 down their mycelium, feed upon the juices of 

 the tree, live for a while in their perfect beauty, 

 and throw off a fresh batch of spores. In the 

 meantime canker follows, and the trees are 

 either destroyed or enfeebled. Now, it is 

 believed that this beautiful little peziza is the 



cause of canker in larch ; true, I have found 



C 



