Consciousness in Plants. 329 



sensitiveness, and the transmission of a stimulus from the 

 exciting point to another, which consequently moves. Yet 

 plants do not, of course, possess nerves or a central nervous 

 system. May we not therefore infer, and wisely so, too, 

 that with animals such structures but serve for the more 

 perfect transmission of impressions, and for the more com- 

 plete intercommunication of their several parts? 



No structure in plants seems more wonderful, as far as its 

 functions are concerned, than the tip of the radicle. Lightly 

 pressed or burnt or cut, it transmits an influence to the upper 

 adjoining part, causing it to bend away from the affected 

 side. But more surprising, however, is the fact that the tip 

 can distinguish between a slightly harder and softer object, 

 by which it is simultaneously pressed on opposite sides. 

 Let the radicle be pressed by a similar object a little above 

 the tip, and it will be noticed that the pressed part does not 

 transmit any influence to the more distant parts, but bends 

 abruptly towards the object. Perceiving the air to be moister 

 on one side than the other, it likewise sends out an influence 

 to the upper adjoining part, which deflects towards the source 

 of the moisture. When excited by light, the neighboring part 

 bends from the light ; but when excited by gravitation, the 

 same part bends towards the centre of gravity. In almost 

 every instance the ultimate purpose or advantage of the several 

 movements can be clearly perceived. Two, or perhaps more, 

 of the exciting causes often act simultaneously on the tip, and 

 one conquers the other, doubtless in accordance with its im- 

 portance for the life of the plant. The course pursued by the 

 radicle in penetrating the ground being determined by the 

 tip, has acquired for it the diverse kinds of sensitiveness which 

 it possesses ; and it is hardly an exaggeration to assert that 

 the tip of the radicle thus endowed, and having the power to 

 direct the movements of the adjoining parts, acts like the 

 brain of one of the lower animals, which organ, seated within 

 the anterior end of the body, receives impressions from the 

 sense-organs, and directs their several movements. 



