The Natural Distribution of Forest- Tree Seeds. 31 



14. Pistillate Flow- 

 ers of the Willow. 



moisture and light, nature has provided many kinds with the means 

 ibr being carried to a greater or less distance. 

 This natural dispersion of the seed may occur in 

 various ways : 



123. Dispersion by the Winds. Most of the pines 

 and firs have their seeds furnished with a thin 

 membranous wing at one end, that enables them 

 to be borne to a considerable distance by the winds. 

 Tho elms have a thin disc entirely around the 

 seed, and the maples have their seeds in. pairs, each 

 side being furnished with a membranous wing. In 

 the ash the seeds have Closely adherent leaves, 

 which enable it to be carried by the winds, and in 

 the hornbeam there is a leaf-like appendage, that 

 aids in its dispersion. In the maples, the pairs 

 of seeds, with symmetrical wings, takes a ro- 

 tary, spinning motion as they fall. The poplars 

 and willows have a downy tuft, which enables 

 them to be carried by the winds, sometimes many 

 miles from the tree where they grew. 



124. The cotton wood, which belongs to the 

 poplar family, derives its name from this dow r ny 

 appendage, which lies abundantly scattered over 

 the ground at the season when it ripens. The 

 bass wood has a heavier seed, suspended on the 

 underside of a leaf-like wing, which causes it to 

 shoot off obliquely as it falls. In some instances, 

 the seeds falling in winter upon a crust of snow, or 

 upon the ice, may glide along before the wind a 



great distance, and in this way the pods of the lo- 16 seed of the Elm 

 cust, and other heavier seeds, in their capsules, or 

 without them, may occasionally be scattered. 



15. Pine Seeds. 



17. Seed of the 

 Birch. 



Of the Agency of Animals in the Planting of Tree 



Seeds. 



125. We often find trees, especially such as bear 

 edible nuts, or stone fruits surrounded by a pulp, growing in situa- 

 tions where the seeds have been dropped by birds or animals. In fact, 

 the squirrels may be called the most industrious and successful 



