392 KEGENEBATION BY MEANS OF CULM'S. 



Indeed it is a well-established fact that even if this latter is cut 

 away, the rhizome already produced upon it will nevertheless con- 

 tinue to grow on and develop into a new shoot with the help of 

 constructive materials derived from the grandparent. 



A clump that has free room for development on every side will 

 go on expanding until the whole of it flowers and dies. On the 

 other hand, in a complete crop, each of the individual trees and 

 clumps composing it can occupy no more space than what is left 

 for it by its immediate neighbours. So long as this space is not yet 

 completely utilised, a clump will go on expanding and producing 

 new shoots year after year. When, however, there is at last no 

 more room left, further useful growth will be impossible unless 

 some of the neighbouring culms are removed by death or the 

 woodcutter. 



Besides expanding by the production of new shoots along the 

 outside, a clump becomes gradually more and more crowded by 

 the development of new shoots also in the midst of the old ones, 

 some species, which form short rhizomes, being especially given to 

 this tendency. Such tendency will be exaggerated in poor, and 

 particularly in shallow, soils, owing to the elongation of the rhi- 

 zomes being restricted by the small quantity of food available. 



We are now able to understand why the culms of each succeed- 

 ing year are, barring accidents of season, fires, &c., larger than 

 those of the preceding year until the maximum size of the species 

 in question in the given soil and locality has been reached. As 

 year succeeds year there is an increasing number of stems to ela- 

 borate constructive materials for the new growth, and the increas- 

 ing size of the stems thus brought about obviously reacts in the 

 same direction. If at any stage of its growth we restrict the 

 further expansion of the clump by cutting out, as soon as it ap- 

 pears, everything in excess of the fixed limit, the size and number 

 of the shoots will continue practically the same from year to year. 

 If each succeeding year we curtail more and more the spread of 

 the clump, the result will be that the size as well as number of the 

 shoots will go on diminishing every year. What precedes may be 

 stated in the form of an aphorism thus : Overctit and the pro- 

 duction will fall off both in size and number of shoots ; cut out the 

 exact amount of the annual production, and the clump will yield 

 the same results year after year ; give rest or cut out less than the 

 annual sum of production, and the size and number of the shoots 

 will go on increasing from year to year until the maximum figures 

 ure attained. 



