ON FRUITS AND SEEDS. 



365 



tend to drive the seed into tlie ground. If, then, the air becomes 

 drier, the awn will again roll up, in which action M. Roux thought it 

 would tend to draw up the seed, but from the position of the hairs the 

 feathery awn can easily slip downward, and would therefore not affect 



Fig. 21, Seed of Stipa pennata. (Natural size.) 



the seed. When moistened once more, it would ascain force the seed 

 farther downward, and so on until the proper depth was obtained. A 

 species of anemone {A. montanci)^ again, has essentially the same ar- 

 rangement, though belonging to a widely separated order. 



