126 DISSEMINATION OF SEEDS. 



world, we are as sure that seeds must be carried to great 

 distances as if we had seen them so carried ; such storms 

 carry leaves, hay, dust, and many small objects to a great 

 height." 



With the peculiar globular shaped fruit of the Plalanus, 

 or button wood-tree, most are familiar. It remains sus- 

 pended like a little ball from the branches of the tree 

 during a large part of the winter until, by the action of 

 wind and snow, it falls to the ground. There it lies 

 until the nutlets separate when each with its tuft of hairs 

 is carried hither and thither by the wind until it reaches 

 a resting-place. 



The styles of the Clematis alba, during the ripening 

 of the seed, develop into long feathery tails which remain 

 attached to the achenia and render the latter fitted to 

 become scattered by the wind. While the pericarps 

 with their richly fringed styles are attached to the 

 receptacle, they give to the vine, as it hangs in festoons 

 from the branches of shrubs and trees, a peculiarly attrac- 

 tive appearance. 



The fruit of some of our forest trees, as the maple, the 

 ash, and the elm, receives the name samara. In all except 

 the first it is an indehiscent, one-seeded fruit, furnished 

 with a membranous wing. This wing which assists in 

 the dispersion of the seed is an outgrowth of the pericarp. 

 In the ash, the wing is terminal ; in the elm, it surrounds 

 the body of the pericarp ; in the maple the fruit is a 

 double samara, that is, it consists of two united indehis- 

 cent pericarps each enclosing a seed and developed at one 

 extremity into a wing. 



The fruit of the Liriodendron tulipifera, tulip-tree, 

 consists of numerous one- or two-seeded winged carpels, 

 dry and indehiscent. These carpels consist of long flat 

 styles imbricated in the form of a cone and, as the seeds 



