MODE OF GEOWTH OF EAMBOOa, 391 



fbrjTiative material necessary for such rapid growth? Having no 

 leaves while this growth is going on, and consisting, as it does, 

 mostly; of hard, woody tissue, it can itself elaborate but little by 

 means of its green superficial covering. The conclusion is thus 

 inevitable that most of the requisite nourishment comes from the 

 rest of the clump, and especially from those in closest connection 

 with it, viz (1) the parent culm, and (2) that from which this latter 

 has been produced. This conclusion has been amply proved by 

 numerous experiments.. 1£ the whole of a clump in full pro- 

 duction is cut back, even during the season of repose when, the 

 rhizomes contain, their maximum, amount ot reserve materials, the 

 new growth will not contain, a. single thick culm, but consist only 

 of a dense mass of switches, , proving the insufficiency of the supply 

 of food to produce any larger growth. The falUng off is more 

 conspicuous, the closer to, the ground the clump is cut, away, for 

 the numerous branches, which high-cut stumps throw, out, elaborate 

 no inconsiderable quantity of food for the production of new shoots. 

 It will be only gradually and after several years that the clump 

 will again produce full-sized shoots, the shoots of each successive 

 year being, bigger than those ofTihe previous year,, just as in the 

 case of a clump, developed normally from, the seedhng. This de- 

 monstrates another important fact, viz., that the larger the parent 

 culms are„ the larger., up to the limits of full size, will be the 

 daughter shoots. This same fact may be proved in a more direct 

 manner thus-: — Cut away all the thick culms by. the base leaving 

 only, ihe switchy shoots, and the production of the following season 

 will be entirely, switchy ; then, on the other hand, cut away every- 

 thing except 1-3 of the large shoots, and in the next, season's 

 growth there will still be found one or more thick culms.. 



A culm in its first year possesses but few branches and hence a 

 \tery limited leaf-apparatus^ and it is not until its third season 

 that it attains. its- fullest development in branches and foliage.. For 

 this reason, and also because the shoots of the year are very, iur 

 sufficiently hgnified, a culm im its- second, season requires for its 

 own use a large part of the food it is able ta assimilate, and it is 

 only in. the third year that it can. spare for the rest of the clump 

 all the constructive materials it elaborates.. Being then in almost as 

 close connection with the shoot of the year as the parent (tw.a- 

 season-old) culm itself is, it eontributes qjaite as much towards the 

 growth of the former as this latter does. Hence for the develop- 

 m.ent of the new rhizome and resulting shoot its preservation is not 

 less essential than the preservation of the direct mother culm itself. 



