126 THE HUMAN SIDE OF TREES 



greater distances than man's motor-driven aero- 

 planes have ever flown. 



All summer long a great many trees devote their 

 principal energy to maturing their seeds and pro- 

 viding them with some sort of flying apparatus. 

 Those of the ash have paper-like wings. The seeds 

 of the elms and maples are equipped with mem- 

 branes as gauzy and delicate as those of a dragon 

 fly. Willow, poplar, and catalpa seeds are attached 

 to tiny balloons. Hop tree seeds have to be satis- 

 fied with a kite-like appendage. The spruces, firs, 

 larches, hemlocks, pines and birches produce winged 

 seeds, with a large number coming from a single 

 pod. The alders, tulips, ashes and elms send forth 

 winged boxes single seeds occupying entirely ma- 

 tured pistils. The parachute-equipped offspring 

 of the pine are given an encouraging push into the 

 world with the bursting of their parent cone. The 

 exploding pods of the wistaria and witch-hazel 

 fairly hurl their children out onto the breeze. 

 Masses of beautifully plumed seeds float from the 

 willows and poplars. 



Next to the wind, the trees depend upon birds 

 and animals in getting about the earth. Strange 

 to say, they seem to prefer to ride inside rather than 

 on the backs of their beasts of burden. As a rule, 

 only the lowlier herbs and seeds choose the outside 



