VI] 



DEVELOPMENT OF PINE-TREE 



77 



and the youngest laterals are already overtopping it, 

 and themselves putting out their own laterals. And, 

 lastly, we observe that the older lowermost principal 

 laterals are no longer growing out so vigorously as the 

 upper and younger ones: in other words the younger 

 laterals are overtaking the lower and older ones in growth. 



Fig. 24. Diagram of an older Pine-tree whose stem has lost its lower 

 branches. 



The consequence is the previous conical or pyramidal 

 shape of the whole crown is rapidly changing to a 

 cylindruid or ovoid form, and this will become more and 

 more marked as the upper laterals tend to catch up the 

 lower in the process of growth. 



As the tree ages, the processes of change above 



