The Larch Disease. 387 



Japanese larch which were certainly attacked by the fungus. 

 Dr Alassee, of Kew, who is the best authority in Britain on the 

 subject, has pronounced that the fungus is the real larch-canker, 

 so that there is no doubt about the matter. 



The trees were grown from seed brought by Mr W. 

 Campbell from Japan, and planted out at Murraythwaite in the 

 autumn of 1899. They are in a pure plantation of Japanese 

 larches (Larix Leptolepis), but very close to a plantation of the 

 common larch, which is badly affected by the disease. As only 

 two trees of the Japanese seem to have been touched, it is cer- 

 tainly less subject than the common larch, at anyrate at present. 

 The fungus Dasycypha Willkommii, or Peziza calycina, is 

 found on flattened deformed parts of the branches. The fruit 

 (about the height of a capital letter) is whitish on the outside, 

 ending above in a tiny orange-yellow cup. Several of these fruits 

 are usually scattered over a deformed swelling of the branch. 

 The orange cup contains thousands of spores, which are carried 

 by the wind or insects to other trees. If a spore happens to fall 

 on a young twig gnawed by a beetle or by squirrels, or on a 

 branch accidentally peeled or broken in any way, it begins to 

 grow, and forms a delicate cobwebby mass of threads, which 

 develops between the wood and the bark, absorbing food which 

 ought to nourish the tree. 



Sometimes the tree by a great effort cuts off the injured 

 branch by a sheet of cork and recovers, but more usually the 

 fungus lives on, year after year, destroying its health and vigour. 



The fungus is decidedly worst in damp, low-lying places ; on 

 mountain sides even the common larch sometimes escapes, as, 

 for instance, at Dalswinton (on the authority of Mr Hattersley). 

 But the present universal system of growing larches in pure 

 plantations, without any other trees between them, must, of 

 course, be particularly favourable to the spread of this or any 

 other fungus or insect pest. Almost every spore of the thousands 

 in a cup will reach another larch, instead of some other tree, 

 which it would not be able to attack, and in this case, of course, 

 it would perish miserably. 



These pure plantations are, therefore, dangerous; the best 

 continental authorities recommend a mixture of larch with 

 deciduous and other conifers, for other reasons as well as the 

 above. 



