80 THE HUMAN SIDE OF TREES 



of a youngster is green and sappy. Old trees ac- 

 cumulate a thick layer of dead, corky cells which 

 present a shaggy, venerable appearance compatible 

 with dignified age, and not unlike in appearance the 

 wrinkles on the face of an aged warrior. The sas- 

 safras tree takes on a rough bark in two or three 

 seasons ; in other words, it ages fast ; but most trees 

 are glad to retain the smoothness of youth for at 

 least ten or twelve years. Like human beings, 

 those trees which are well protected retain their 

 youth much longer than those which have many 

 hardships and struggles. The beech presents an un- 

 ruffled almost papery surface or skin all through 

 life. It is therefore very susceptible to injury. 

 Each variety of tree soon develops a definite, easily 

 recognisable bark pattern, which serves as an ad- 

 mirable means of identification. 



Besides growing concentrically in wood and bark 

 a tree grows linearly at each twig. Each season 

 sees on each small branch the repetition of the first- 

 year process which developed the infant tree from 

 a single leaf into an herbaceous shoot. The end of 

 each branch grows out a certain length and then 

 provides itself with a terminal bud. The number 

 of bud rings on a branch indicates its age, while 

 the distance between them shows how much it grew 

 each year. Each falling leaf makes its scar and the 



