70 



PLANTS 



carried by the wind to great distances. Larger seeds in many 

 cases have special contrivances in the form of sails, parachutes, 

 or feathery or hair-like appendages which offer such a large 

 surface to the wind that they may also be carried by it in spite 

 of their larger size. Seeds swallowed by animals are frequently 

 not digested and may be carried abroad by this agency. 



1 68. But aside from the protection which the fruit tissues may 

 give the seed in some instances, it is often the function of the 



Fig. 34. — A leaf of Bryophyllum developing new plantlets by budding at the 



edge of theleaf. 



fruit to provide for the dissemination of the seed. This object 

 may be accomplished in an endless variety of ways; sometimes 

 by mechanically scattering the seed when the fruit opens; 

 sometimes by the development of hold-fast organs which cause 

 the fruit to cling to passing animals; or again by means of para- 

 chutes and sails by which the fruit is carried on the wind; or by 

 floats on which the fruit drifts with the current of water. Edi- 

 ble fruits of all sorts are carried by animals from place to place 

 and the seeds scattered in this way. In some cases the larger 

 part of the plant is concerned in the process of scattering seed. 



