Vegetal Causes. 157 



stitution of vegetals has, however, hardly been begun. 

 That the number and kind of commingled elements 

 in a plant bear an important relation to the nature 

 of the product evolved is undoubted. Indeed, so 

 far as the phenomena of evolution are concerned, 

 probably as much variation is induced by chemical 

 affinities and antagonisms as by histological and 

 morphological displacements. Judging from analogy, 

 the simplest plants contain the fewest chemical ele- 

 ments in combination, while the most complex con- 

 tain the most numerous. Here, however, we wait 

 for proof. Still, it stands to reason that as increasing 

 complexity of moving substance involves more and 

 more complex motion of parts, the greater the number 

 of elements in an organism the greater will be its 

 internal disturbance, and consequently the greater 

 visible manifestation of this disturbance in external 

 form and function. As M. Lefevre says :— " The 

 vegetal elements constitute a veritable vortex of 

 atoms of unstable components, because nitrogen, 

 carbon, and hydrogen possess but few and weak 

 affinities of combination, consequently do not form 

 aggregates solidly fused together." * 



Some of the constituents of plants are equally 

 common to minerals, but they do not combine in 

 the same proportions. The metallic elements in a 

 mineral necessarily preponderate over the non- 

 metallic. Hence, the kind of elements does not 

 constitute the sole difference between hard, unyield- 



'"' Philosophy. Eng. Trans. P. 471. 



