VI] 



DEVELOPMENT OF FORM 



71 



have persisted having developed to limbs of approximately 

 equal value and the impossibility of deciding which of 

 them should be regarded as the upward continuation of 

 the axis. It is evident that many of the laterals and 

 of their branches of the first, second and higher orders 

 have been lost, and nevertheless the general contour of 

 the crown as a pyramid with rounded apex, or a more or 

 less dome-shaped structure, has been attained as perfectly 



Fig. 18. Fig. 19. 



Fig. 18. First stage in development of the Lime- Willow type. 

 Fig. 19. Second stage in development of the Lime- Willow type. 



as in the case of the Pine, where the axis runs right 

 through and the lateral branches come off so regularly, 

 and themselves ramify further in a symmetrical manner 

 (cf. Figs. 22—25 and Fig. 1). 



As will be seen from the more detailed analysis of the 

 methods of branching, the dominant factor in shaping the 

 periphery of the tree is in both cases the same, namely 

 light ; but the chief point we are at present concerned 



