io6 Trees, Stars, and Birds 



very small amounts of water from the frozen soil ; so 

 trees with broad, thin leaves drop them before the cold 

 season comes. During the months when the air is 

 warm and water is abundant they run a great food 

 factory and store in their branches, stems, and roots 

 the surplus food which they make. On this surplus they 

 live through the winter, and from it they build in the 

 spring their flowers, leaves, and young twigs. The 

 working season of most deciduous trees is even shorter 

 than we think, for the delicate leaves cannot appear 

 until after the season of frost is over, and they fall 

 from many trees as soon as the first frosts of autumn 

 come. 



On the other hand, the leaves on most evergreen trees 

 are small, and they are tough and leathery so that they 

 resist cold and drying. A tree of this kind does not have 

 the great spread of leaf surface that a deciduous tree 

 has. At no time can it manufacture food as rapidly 

 as a deciduous tree does when it is in full leaf ; yet the 

 leaves of evergreens are able to build some food for the 

 tree during the greater part of the year, whereas the 

 trees that lose their leaves at the end of summer cannot 

 add to their stock of nourishment until the following 

 spring. In some locations the slower and steadier 

 method of the evergreen succeeds better than the plan 

 of rapid work for a shorter part of the year followed by 

 the deciduous tree. 



Where the deciduous and evergreen types succeed. 

 In most parts of the temperate zone where the soil is 

 deep and moist, as in rich river bottoms, and where 

 the growing season is long and the air moist, the de- 



