THE PINE. 421 



thrown off, there the decay ceases, the interior part or 

 knot being of hard consistence and full of resin. 



Besides the heart-rot to which Matthew says the Scotch 

 fir is liable in wet ungenial soil, there is another disease 

 to which it is subject, and which proves frequently fatal 

 in our own and other plantations in the north of England, 

 but which hitherto has not been observed to affect the 

 trees in their native forests or in the highland districts. 

 This is caused by the attack of a cryptogamic plant, the 

 JEcidium pim, beautifully figured in Dr. Greville's " Cry- 

 ptogamic Flora," pi. 7. vol. i. In general, the leaves only 

 are affected, and then seldom to such an extent as seriously 

 to injure the tree ; but, in the instances to which we al- 

 lude, it attacks the bark, sometimes of the larger branches, 

 but more frequently of the main stem itself, and this, 

 in many instances, when the tree is thirty or forty years 

 old. When the iEcidium attacks a tree, the place is easily 

 recognized by the swollen appearance of the bark, and 

 it becomes still more conspicuous when the cysts begin 

 to discharge the orange-coloured powder, or sporidia, with 

 which they are filled. The bark, by the growth of this 

 parasite, becomes completely disruptured, and its texture 

 destroyed at the place of attack, and in consequence a 

 great flow of resin ensues, and the tree usually dies in the 

 course of a few months. Previous to the appearance of 

 the JEcidium, we have not observed that the trees attacked 

 showed any symptoms of decay or ill-health, though we 

 are strongly inclined to believe that there must be some 

 predisposition in such individuals to receive the sporidia 

 of the parasite. The only accident of any consequence 

 to which the Pine is liable results from heavy falls of 

 snow, which, when unattended by wind, sometimes accu- 



