x.] "CANKER": THE LARCH DISEASE. 239 



the centre of the patch. Now it is a well-known fact 

 in the hill-forests of Switzerland, Germany, Austria, 

 &c., that heavy falls of snow often load the branches 

 until they bend down to the ground, and the bark in 

 the upper angle where the branch joins the stem 

 is ruptured ; similar cracks are also caused by the 

 bending down of the branches under the weight of 

 water condensed from mists, &c. If a spore alighted 

 near such a place, the rain would wash it into the 

 crevice, and it would germinate in the moisture 

 always apt to accumulate there. This certainly 

 accounts very completely for the situation of the 

 dead branch, which of course would at once suffer 

 from the mycelium. Another way in which such 

 wounds as would give access to the parasite might 

 arise, is from the blows of hailstones on the still 

 young and tender cortex. 



But probably the most common source of the 

 crevices or wounds by which the fungus gains an 

 entry is frost ; and to understand this we must 

 say a few words as to what is known of the larch 

 at home in its native Alps. 



It is well known, since Hartig drew attention 

 to the fact, that in the high regions of the Alps 

 the trees begin to put forth their shoots very late : 

 the larch in the lowlands of Germany and the British 



