150 Our Field and Forest Trees 



reach the newest cork, and can go no farther. So 

 their different ways of wearing their new union- 

 suits causes a great difference in the appearance 

 of the trees, even in midwinter. 



When we see the deep rifts in the bark of the 

 common locust and the high, rough ridges between 

 them, we know that In this tree the newest cork 

 lies far below the surface of trunk and boughs. 



The sugar maples, on the contrary, wear their 

 new cork robe just beneath their outer bark, and 

 so likewise do the beeches. So the rents in the 

 bark of these trees are shallow. 



But, shallow or deep, they serve to remove the 

 outer bark, which cannot stretch, from the living 

 trunk, which must expand. The skins of animals 

 can stretch. But the bark, which is the skin of the 

 tree, cannot stretch, but gets torn off bit by bit. At 

 the base of pine trees in the woods, and all around 

 the boles of plane trees, lie flakes of bark which 

 dropped away from the living trunk. 



Initials cut in the outer bark, or blazes which 

 have not gone deep, will lose their distinctness as 

 the bark around them drops, little by little, and 

 will disappear in from ten to twenty years. 



The letters cut deep into the young wood dis- 

 appear also, after awhile, but in a different way, 

 and for a different reason. They become buried 

 from sight under many layers of new wood and 

 bark. 



Most of us have had difficulty from time to time 



