12 THE TREE BOOK 



the cambium layer, which promotes the new 

 growth, is dead. New wood, however, will be 

 added to the collar which encircles it. This 

 will go on year after year, unless some outside 

 force intervenes; the collar will grow tighter 

 and tighter and the pressure of the young wood 

 win become so strong that the old dead wood 

 will be pinched and ready to snap at the first 

 chance. A gust of wind, a heavy fall of snow, 

 or even its own weight may break it off finally. 

 Each new year's layer of wood will build around 

 the ring encircling the dead stump, until finally 

 its disk will be covered by a patch of smooth 

 bark, such as we noted on the first tree. In the 

 course of a few years this, too, wiU vanish, and 

 the record of the dead branch will be buried 

 forever, unless perchance the tree is felled and 

 the action of saw or axe brings the stump disk 

 to light. 



Here is a great, lengthwise scar on the trunk 

 of a towering old monarch of the forest. What 

 does it mean? Surely it is not an example of 

 Nature's pruning? No, indeed. It is the work 

 of Jack Frost. See, it is on the southwest side 

 of the tree. Probably after a succession of 

 warm days, the tree was deceived into thinking 

 spring at hand: the rootlets began to drink 

 thirstily, and the water they absorbed moved 



