HOW BIG TREES GROW 43 



abont forty years old. Some trees may bear seed at 

 from six to ten years of age but very often such seed 

 fails to germinate. 



Mother Nature seems extremely anxious to have tree 

 species distributed as widely as soil and climate will 

 permit and so we find various devices to secure the scat- 

 tering of seeds. 



Willow and poplar seeds are attached to a fleck of 

 down, and may be carried long distances by the wind. 

 Ash, maple and tulip trees have seeds with long wings 

 which cause them to whirl in the air as they fall, 

 greatly increasing the distance they may be carried by 

 the wind. Some seeds like chokecherry or red cedar 

 have a fleshy coat which is eaten by the birds who thus 

 carry the stone or seed proper long distances. Still 

 other trees, like chestnut, hickory and walnut, are 

 largely distributed by squirrels since the nuts are too 

 heavy to be carried by the wind and will roll or bound 

 only short distances from the tree. 



Most of the evergreens have winged seeds borne on 

 the inside of the cone scales and in spite of their com- 

 paratively small wings they can be carried long dis- 

 tances in the autumn winds. An island lying one-half 

 mile from the nearest shore of an Adirondack lake 

 was completely burned over some years ago. All the 

 trees were killed, the shrubs were consumed and the 

 litter was burned down to the mineral soil thus de- 

 stroying any seed which had previously fallen. Never- 

 theless within a few years a splendid stand of spruce 

 seedlings was started from seed trees on the shore, the 

 winged seed having been blown out to the island by 

 the strong wind. 



Seed in favorable years is produced in enormous 

 quantities but a large portion of it never germinates. 



