GYRA TION OF PLANTS. 169 



sane person would arrive at the conclusion that this 

 subterranean habit is of some service to the plant ; 

 that all this elaborate adaptation for burrowing is 

 designed for some purpose, and is not merely 

 accidental ; and that the smaller contributories to the 

 act, whilst they aid in its consummation, do so to 

 that intent. 



We have endeavoured to show, in this chapter, 

 that the rotation, or oscillation, of the growing parts 

 of plants is a phenomenon which is exceedingly 

 common ; that it exhibits itself first in the young 

 radicle soon after it emerges from the seed ; that 

 it is very prevalent in the cotyledons or seed-leaves, 

 and in the plumule or growing point ; that the 

 young parts of all plants evidence its presence 

 to a greater or less extent ; that leaves possess 

 the faculty as well as cotyledons ; and, finally, that 

 not only do flower-stems oscillate, but that after the 

 flowers have withered the same phenomenon accom- 

 panies the ovary of those plants which mature their 

 seeds beneath the surface of the soil. 



We have, by the way, illustrated the peculiarly 

 sensitive character of the tip of the radicle, and 

 endeavoured to indicate its service to the plant. It 

 has only been our aim to summarise what is known 

 of these phenomena, and to present the most striking 

 features as subjects for thoughtful reflection, and as 

 incentives to closer observation. 



