WOUNDS 241 



It but rarely happens that adventitious buds originate above- 

 ground on uninjured portions of a plant, whereas endogenously 

 developed buds occur regularly on the roots of many species of 

 trees (root-suckers). On the other hand, their occurrence on the 

 callus or investing layer of a wound is a frequent phenomenon 

 (Fig. 151). There they originate close beneath the surface in 

 the meristematic parenchymatous tissue, where they form their 

 ring of vascular bundles, which internally are in intimate union 

 with the wood of the callus. 



Adventitious roots, which may occur endogenously both on 

 the uninjured cortex and on wound-tissues, have a precisely 

 similar origin. 



THE VARIOUS KINDS OF WOUNDS 1 



Of the endless variety of wounds, we need select for discussion 

 only a few of the more generally interesting. 



BARKING BY GAME 



Barking (peeling) by red deer is usually confined to conifers, 

 though dicotyledonous trees, for example the beech, are also 

 similarly attacked less frequently. Fallow deer, on the other 

 hand, abrade most if not all of our forest trees, though certain 

 trees, e.g. the ash, are specially liable to attack. Roe deer, 

 hares, and rabbits also bark trees under certain circumstances. 

 Roe deer cause a special form of injury by rubbing off the bark 

 of young trees with their newly formed horns. 



During winter, game bark trees for want of food, the starchy 

 cortex of smooth-stemmed trees being nibbled to satisfy hunger. 

 In summer, when trees are easily peeled, the more characteristic 

 feature of the injury consists in the separation of large flaps of 

 cortex, and this is frequently done to a considerable height. 

 Views differ as to the motive of peeling during summer. It ap- 

 pears to me most probable that the game regard the rich store of 

 sugar in the cortex as a toothsome morsel. Some believe that 

 the animals find an important aid to digestion in the tannin of the 

 cortex. Game are also said to peel trees for the sake of the lime 

 contained in the bark. Excellent results attended the feeding 



1 R. Hartig, Zersetzungerscheinungen, pp. 67 et seq. 



R 



