OBJECTIONS TO THE THEORY 385 



nascent condition in many plants which have not become 

 climbers. This is the case: I observed that the young 

 flower peduncles of the above Maurandia curved them- 

 selves a little toward the side which was touched. Mor- 

 ren found in several species of Oxalis that the leaves and 

 their foot-stalks moved, especially after exposure to a hot 

 sun, when they were gently and repeatedly touched, or 

 when the plant was shaken. I repeated these observa- 

 tions on some other species of Oxalis with the same 

 result; in some of them the movement was distinct, but 

 was best seen in the young leaves; in others it was ex- 

 tremely slight. It is a more important fact that, according 

 to the high authority of Hofmeister, the young shoots and 

 leaves of all plants move after being shaken; and with 

 climbing plants it is; as we know, only during the early 

 stages of growth that the foot-stalks ^nd tendrils are 

 sensitive. 



It is scarcely possible that the above slight move- 

 ments, due to a touch or shake, in the young and grow- 

 ing organs of plants, can be of any functional importance 

 to them. But plants possess, in obedience to various 

 stimuli, powers of movement, which are of manifest im- 

 portance to them; for instance, toward and more rarely 

 from the light — in opposition to, and more rarely in the 

 direction of, the attraction of gravity. When the nerves 

 and muscles of an animal are excited by galvanism or by 

 the absorption of strychnine, the consequent movements 

 may be called an incidental result, for the nerves and 

 muscles have not been rendered specially sensitive to 

 these stimuli. So with plants it appears that, from 

 having the power of movement in obedience to certain 

 stimuli, they are excited in an incidental manner bj a 



