i88i.] 
Life and its Basis, 
9 
purpose. If such individual choice could be clearly proved, it 
would seem to carry with it the admission of the existence 
of a physical entity in each separate plant, and indeed in 
every separate cell, which would be equivalent to regarding 
vegetable life as an assemblage of such entities, undistinguish- 
able from those of animals. On this subject, however, we 
cannot do better than accept the opinion expressed by Mr. 
Darwin in his new work on “ The Power of Movement in 
Plants.” He traces the remarkable actions of many plants, 
which he describes under the name of circumnutation, to the 
influence of external conditions, as light, heat, electricity, 
&c., causing various contractions and expansions of their 
cellular tissues, rather than to the existence of any internal 
cause. But this interesting though admittedly obscure 
branch of vegetable physiology abounds with instances of con- 
trivance, which clearly prove design, and indicate the presence 
of will and purpose in an unmistakable manner, somewhere. 
It has become an axiom in physiology that chemistry is 
controlled and often suspended by life. The explanation of 
this phenomenon by our present theory is easy and direCt. 
Both activities are in reality manifestations of the same 
power working in different ways, and the last dominates the 
other, when the purposes of the living organism are to be 
answered by it. When these purposes have been fulfilled, 
and the living state has ceased to exist, the ordinary chemi- 
cal forces predominate, and dissolve the organism into its 
former elements. 
I have more than once had occasion to advert to the con- 
ditions in which living vegetation exists, such as air, water, 
light, heat, &c. And there is no question as to the large 
part these conditions play in the ever-shifting scenery of this 
most beatiful department of Nature. But with regard to the 
last-mentioned influences, something more remains to be 
said. Believing, as I do, in the highly probable doCtrine 
that the three constituents of the solar ray, heat, light, and 
aCtinism, are only different rates of vibration in the same 
medium, viz., the aether, and that, moreover, this medium is 
suffused through all other material bodies, and, in fact, 
forms a constituent part of them, — and especially so in the 
case of air and water, — l am fully prepared to recognise the 
aether combined with protoplasm and its resultants in vege- 
table organisms, as the instrument employed in vital pro- 
cesses, I regard this medium, whether existing in space or 
in solid bodies, as, beyond all others, the most wonderful 
form of matter of which we have any knowledge, and that 
not only the solar emanations, but electricity, magnetism, &c., 
