x.] "CANKER": THE LARCH DISEASE. 231 



consternation and difference of opinion as the 

 " larch-disease," and even now there is far too 

 little agreement among foresters either as to what 

 they really mean by this term, or as to what causes 

 the malady. The larch, like other timber-trees, is 

 subject to the attacks of various kinds of fungi 

 and insects, in its timber, roots, and leaves ; but 

 the well-known larch-disease, which has been 

 spreading itself over Europe during the present 

 century, and which has caused such costly 

 devastation in plantations, is one of the group of 

 cancerous diseases the outward and visible signs 

 of which are manifested in the cortex and young 

 wood. 



The appearance presented by a diseased larch- 

 stem is shown in Fig. 35. In the earlier stages 

 of the malady the stem shows dead, slightly 

 sunken patches, #, of various sizes on the cortex, 

 and the wood beneath is found to cease growing : 

 it is a fact to be noted that the dead base of a 

 dried-up branch is commonly found in the middle 

 of the patch. The diseased cortex is found to 

 stick to the wood below, instead of peeling off 

 easily with a knife. At the margins of the 

 flattened patch, just where the dead cortex joins 

 the normal living parts, there may frequently be 



