Dispersion of Fruits and Seeds. 



213 



FIG. 128. 



Seed pod of Trumpet Creeper broken open and winged 

 seeds fallen out. Reduced. 



those seeds and 



fruits with out- 

 growths in the 



form of sails or 



wings. In the 



case of elms, 



maples, Ailan- 



thus, etc. (a, d, 



n, Fig. 127), the 



border of the 



ovary grows out 



in the form of a 



membrane ; and 



in the seeds of the Catalpa and trumpet creeper (Fig. 128) 



the walls of the seeds behave in a similar manner. 



One of the 

 best devices to 

 give buoyancy 

 to light seeds or 

 fruits is an out- 

 growth of hairs, 

 such as is found 

 on the fruits of 

 dandelion or 

 Anemone, or on 

 the seeds of the 

 poplars, milk- 

 weeds (Fig. 1 29), 

 cotton of com- 

 merce, etc. 



In the cotton- 

 wood (Populus 



FIG. 129. 



Seed pod of Asclepias cornuti and escaping seeds. The 



tuft of hairs on each seed acts as a parachute. Reduced. 1H 111 I IJ 6 V d j , 



