20 ELEMENTARY FORESTRY. 



other trees have a decidedly shrivelled appearance, which disap- 

 pears after a few days of mild weather. Soft Maple trees stand- 

 ing on dry land will sometimes in the spring appear to have been 

 dried out and to have become partly or entirely dead. . It is 

 probable that during our coldest weather very little, if any, 

 moisture can be supplied from the roots, which may account for 

 this shrivelled condition. 



Second Growth. Sometimes warm, moist weather in late 

 autumn will cause trees to start a strong second growth in 

 October, which draws on the stored plant food and perhaps 

 exhausts it, and winter sets in before the tissues have again 

 become hard and stored with food. In such cases trees are 

 liable to injury. No characteristic of hardiness is more impor- 

 tant in plants than that of early maturity of wood. 



One part of the tree may start into growth without regard 

 to the conditions of the other parts. For instance, a branch 

 brought into a warm room in winter without severing it from 

 the tree will grow for some time. Sun scald is probably due 

 to the bark on the side most exposed to the sun starting into 

 growth very early, after which a sudden freeze destroys the 

 young cellular tissue. 



