THE W1LDWOODS 



9 



Trees differ very much in this respect. A poplar tree 

 is old at a hundred and fifty years ; a cypress lives to be 

 five hundred years and more ; and some of the large red- 

 woods, the u bigtrees," attain so great an age that the 

 older members of this 

 group began life long 

 before Christ was born. 



Note that smooth- 

 barked spot on yonder 

 rough-barked oak. That 

 is the place where a limb 

 projected many years 

 ago, when the tree was 

 smaller. The limb died, 

 decayed, broke off near 

 the trunk, and the place 

 healed over. Being much 

 younger, the bark at that 

 spot is smoother. Some- 

 times these limbs do not break off e&rly enough, or the 

 stub is too large, like the many you see on these white 

 oaks ; then the tree can never cover up the stub. The 

 large knot hole, from which we saw the squirrel come 

 out, is a similar case; but there the stub decayed, and 

 the decay proceeded along the limb into the trunk and, I 

 fear, did much mischief ; for such a trunk does not make 

 much sound timber. 



FIG. 5. Badly Healed Knot 



a, wood of the knot; b and c, wood callus of 

 the stein covering the wound ; shaded por- 

 tion, decayed wood; black part, a cavity 

 remaining 



