308 MISCELLANEOUS OBJECTIONS TO THE [Chap. VIL 



With respect to the sensitiveness of the foot-stalks of 

 the leaves and flowers, and of tendrils, nearly the same 

 remarks are applicable as in the ease of the revolving 

 movements of twining plants. As a vast number of 

 species, belonging to widely distinct groups, are endowed 

 with this kind of sensitiveness, it ought to be found in a 

 nascent condition in many plants which have not be- 

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

 young flower-peduncles of the above Maurandia curved 

 themselves a little towards the side which was touched. 

 Morren found in several species of Oxalis that the 

 leaves and their foot-stalks moved, especially after ex- 

 posure to a hot sun, when they were gently and repeat- 

 edly touched, or when the plant was shaken. I repeated 

 these observations 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 extremely 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 

 and 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 impor- 

 tance to them. But plants possess, in obedience to vari- 

 ous stimuli, powers of movement, which are of manifest 

 importance to them; for instance, towards and more 

 rarely from the light, — ^in opposition to, and more rare- 

 ly in the direction of, the attraction of gravity. When 

 the nerves and muscles of an animal are excited by gal- 

 vanism or by the absorption of strychnine, the conse- 



