171 



exception of the upper buds, until they strike, i.e. develop roots. 

 The removal of the transpiring leaves from the cutting also, to 

 some extent, serves the same purpose. In India large posts 

 of Boswellia serrata, Erythrina suberosa and other species which 

 have been placed in village fences may often be seen which have, 

 after the manner of cuttings, developed roots from the base and 

 shoots from the upper end and thus become independent trees. 



149. In the case of many species, 



the felling of the tree results in a more or less vigorous develop- Poiiard- 

 ment of callus from the living tissues on the wounded shoots, 

 surface in which adventitious buds may arise, while the wound an 

 also often stimulates the cambium to form adventitious buds suc kers. 

 elsewhere on the stump or on the roots. If now there is a suffi- 

 cient stock of food materials in the stump, or roots, or both, 

 a vigorous development of shoots from the adventitious buds 

 in the callus, or from the adventitious or dormant buds 

 elsewhere on the stump, or from the adventitious buds 

 on the roots, may result. When the young shoots arise 

 on, or close to, the cut surface, the latter is usually quickly 

 covered over by the healthy tissue at the base of the vigorous 

 young shoots and, the access of air and water being thus 

 obstructed, the spread of decay into the stump and root 

 system is prevented. When the stump of the tree is high 

 and the shoots arise at some distance from the ground 

 they are usually known as pollard- shoots, whereas if the tree is 

 cut low and the shoots arise close to the ground they are called 

 stool -shoots, or coppice- shoots, while the shoots springing from the 

 roots are termed root-suckers. Root- suckers usually develop 

 young roots of their own, and this often occurs also with stool- 

 shoots which arise at, or near, the surface of the ground. By 

 directly wounding the roots themselves and by thus stimulating 

 the development of callus, and of adventitious root-and-shoot- 

 buds on, and near, it, the production of root-suckers may often 

 be increased. When considering the phenomena here alluded 

 to, care must be taken to distinguish those cases in which 

 the individual plant is merely trying to recover from the 

 severe injury which it has received from those in which a more 

 or less complete process of reproduction may be recognised, 

 consisting in a division of the mother-plant and the establishment 

 of new and independent individuals. The latter, for instance, 

 occurs when root-suckers become independent of the mother- 

 tree and are furnished with vigorous root -systems of their own. 

 The same thing also appears to occur in cases where stool-shoots 

 produce roots of their own which, owing to the rapid disinte- 



