SCIENCE-GOSSIP. 



187 



has given rise to other shoots bearing leaves and 

 acorns, and though still green, yet soon in their 

 turn to become woody. 



Length of Internode.— In the more vigorous, quick- 

 growing examples of the oak, the internodes of the 

 yearly shoot are often of the length of two or more 

 inches. This applies to the middle portion of the 

 shoot, for the very lowest and earliest formed inter- 

 nodes are scarcely at all developed, whilst those 

 nearer the tip and which have been formed late in 

 the season are shorter and shorter, so that the last- 

 formed leaves, and the buds in their axils, are 



The same things occur to these branches in their 

 turn ; each of them, both terminal and lateral, 

 comes to an end in a rosette of leaves (through 

 the shortening of the internodes as the season 

 advances), the buds formed in the axils of these 

 leaves forming a crown at the tip of the shoot, and 

 the main axis preserving the same direction from 

 year to year, so that we may sometimes trace it 

 from the main trunk almost to the last year's 

 shoot. 



This mode of growth is what we commonly find 

 in the sessile-fruited oak, but it is by no means 



Qtiercus pedunculata, Ehrt. (Flowering state.; 



grouped as a rosette or crown at the top of the 

 shoot. 



Comparative vigour of buds. — The terminal bud 

 is, so long as the tree is in the height of vigorous 

 youthful growth, usually larger, more prominent, 

 and with more force of development than the 

 others which surround it. Hence the shoot which 

 springs from it takes the lead, so that each season's 

 growth is continuous with that of the preceding, 

 whilst the leader is surrounded by three or four 

 smaller branchlets starting in umbellate fashion 

 from the internodes just below its own point of 

 origin. All of these, both leader and lateral shoots, 

 may bear flowers and, in due season, acorns. 



confined thereto, for it occurs, although less gene- 

 rally, in the pedunculate oak. 



In this latter, and more particularly as the tree 

 grows older, or becomes less vigorous, we find 

 another mode of growth. The lateral buds of 

 the crown or rosette are frequently stronger and 

 more vigorous than the central one. When this 

 is the case one or more of these lateral (axillary) 

 buds will develop into shoots, whilst the central 

 (terminal) bud remains dormant. The direction 

 taken by these shoots makes a wide angle — 

 almost a right angle — with that of their parent 

 shoot, and thus is laid the foundation of that 

 zigzag or elbowed branching which we regard 



