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 suppl'ed 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 seald 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. 
