ANIMALS AND VEGETABLES. 41 



of two faculties or functions in the animal, that are wanting in the 

 vegetable, sensibility ', or the faculty of consciousness and feeling ; and 

 motility, or the power of moving at will the whole body or any of its 

 parts. Vegetables are possessed of spontaneous, but not of voluntary 

 motion. Of the former we have numerous examples in the direction 

 of the branches and upper surfaces 9f the leaves, although repeatedly 

 disturbed, to the light ; and in the unfolding and closing of flowers at 

 stated periods of the day. This, however, is distinct from the sensi- 

 bility and motility that characterize the animal. By sensibility man 

 feels his own existence, becomes acquainted with the universe, ap- 

 preciates the bodies that compose it; and experiences all the desires 

 and inward feelings that solicit him to the performance of those ex- 

 ternal actions, which are requisite for his preservation as an individual, 

 and as a species ; and by motility he executes those external actions 

 which his sensibility may suggest to him. 



By some naturalists it has been maintained, that those plants, which 

 are borne about on the waves, and fructify in that situation, exhibit 

 examples of the locomotility, which is described as characteristic of 

 the animal. One of the most interesting novelties in the monotonous 

 occurrences of a voyage across the Atlantic towards the Gulf of Flo- 

 rida is the almost interminable quantity of Fucus natans, Florida 

 weed or Grulf weed, with which the surface of the ocean is covered. 

 But how different is this from the locomotion of animals ! It is a 

 subtlety to conceive them identical. The weed is passively and uncon- 

 sciously borne whithersoever the winds and the waves may urge it ; 

 whilst animal locomotion requires the direct agency of volition, of a 

 nervous system that can excite, and of muscles that can act under such 

 excitement. 



The spontaneity and perceptivity of plants must also be explained in 

 a different manner from the elevated function of sensibility on which 

 we shall have to dwell. These properties must be referred to the fact 

 of certain vegetables being possessed of the faculty of contracting on 

 the application of a stimulus, independently of sensation or conscious- 

 ness. If we touch the leaf of the sensitive plant, Mimosa pudica, the 

 various leaflets collapse in rapid succession. In the barberry bush, 

 Berberis vulgaris, we have another example of the possession of this 

 faculty. In the flower, the six stamens, spreading moderately, are shel- 

 tered under the concave tips of the petals, till some extraneous body, 

 as the feet or trunk of an insect in search of honey, touches the inner 

 part of each filament, near the bottom. The susceptibility of this part 

 is such, that the filament immediately contracts, and strikes its anther, 

 full of pollen, against the stigma. Any other part of the filament may 

 be touched without this result, provided no concussion be given to the 

 whole. After a while, the filament retires gradually, and may be again 

 stimulated ; and when each petal, with its annexed filament, has fallen 

 to the ground, the latter, on being touched, shows as much sensibility 

 as ever. 1 



These singular effects are produced by the power of contractility or 



1 Sir J. E. Smith's Introduction to Botany, p. 325. 



