THE SEEDLING AND YOUNG PLANT 75 



numbers of these Lammas shoots every year, and the 

 tendency to produce them seems to be capable of being 

 inherited. 



The process of sprouting, or putting forth the shoot 

 from the bud, is the same in all the cases. As the 

 temperature and other conditions improve in the spring, 

 for instance, the process of cell-division in the growing- 

 point (and its derivatives, the young leaves, &c.) goes on 

 rapidly, and the stores of nourishment already there and 

 in the pith and other tissues close at hand are used up. 

 This originates a series of currents of food materials set- 

 ting slowly towards these centres of consumption from 

 other parts of the tree, and very soon the numerous cells 

 developed begin to absorb water with relatively enor- 

 mous rapidity and vigour. This brings about two chief 

 changes the rapid elongation of the parts of the cone 

 situated between the points of insertion of successive leaves 

 (i.e. the internodes), and the almost simultaneous expan- 

 sion of the hitherto small and folded leaves. Thus the 

 rapid extension of the shoot is due almost entirely to the 

 energetic absorption of water into cells for the most part 

 already in existence. The chief changes which follow 

 consist in the perfection of the structures the develop- 

 ment and thickening of vascular tissues, cell-walls, &c. 



This process of rapid extension does not occur in the 

 internodes between the bud-scales, or, at any rate, to a 

 slight degree only, just sufficient to enable the shoot to 

 throw the scales off; hence the base of the outgrown 

 shoot shows a number of small scars in a close spiral. 



