310 ENGLISH ESTATE FORESTRY 



often crippled to such an extent that it renders them quite 

 useless for economic purposes. The attacked trees are in 

 much the same position as larch attacked by Peziza Wil- 

 kommi, although the absence of resin in hardwoods renders 

 the attack of the latter more deadly, and also gives it a 

 different aspect. The fructifications of this fungus are so 

 minute that they may easily escape notice, but a careful 

 search will reveal them on the margins of the cankers as 

 bright red dots about the size of the head of a small pin. 

 The mycelium, which perpetuates the canker in the same 

 way as that of Peziza Wilkommi, spreads in the tissues of the 

 wood, and Hartig believed that it was capable of producing 

 cankers from within, and independent of outside infection. 



On healthy trees and favourable situations this fungus 

 rarely gives much trouble, nor does it occur over sufficiently 

 large areas to occasion much alarm. Partly suppressed trees, 

 or those growing in wet, stagnant spots, are most likely to 

 become attacked, and in such situations it is doubtful if the 

 trees would be of much greater value if the fungus were 

 absent. Cutting them out, and removing them from the 

 wood, is the only practical remedy, if remedy it can be called, 

 for it is not at all clear that the fungus has any great 

 power of spreading or propagating itself on trees in average 

 health. 



In conclusion, it may be said that the suppression of all 

 woodland foes, whether animal or vegetable, depends largely 

 upon the aid which nature gives in the work. In many 

 cases the forester is almost powerless in the matter. Fungi, 

 for instance, which spread and multiply by means of millions 

 of invisible spores, can only be detected in their work after 

 the damage is done. Insects, again, such as the larch aphis, 

 or caterpillars of various kinds, come and go in a way which 

 it is almost impossible for a human being to hinder or prevent. 

 The best and easiest way of preventing or discouraging attack 

 by any of these foes, with the exception, perhaps, of squirrels, 

 rabbits, mice, etc., is that of giving each species of tree the 

 soil and situation best qualified to meet its requirements, and 

 to maintain its perfect health and vigour. Many insects, 

 and certainly the majority of fungi, only attack trees which 



