Fig. 117.—Abolition of Response in Nerve, Plant, and Metal by the Action of the same ‘Poison’Fig. 117.—Abolition of Response in Nerve, Plant, and Metal by the Action of the same ‘Poison’The first half in each set shows the normal response, the second half the abolition of response after the application of the reagent.
Fig. 117.—Abolition of Response in Nerve, Plant, and Metal by the Action of the same ‘Poison’
The first half in each set shows the normal response, the second half the abolition of response after the application of the reagent.
Thus living response in all its diverse manifestations is found to be only a repetition of responses seen in the inorganic. There is in it no element of mystery or caprice, such as we must admit to be applied in theassumption of a hypermechanical vital force, acting in contradiction or defiance of those physical laws that govern the world of matter. Nowhere in the entire range of these response-phenomena—inclusive as that is of metals, plants, and animals—do we detect any breach of continuity. In the study of processes apparently so complex as those of irritability, we must, of course, expect to be confronted with many difficulties. But if these are to be overcome, they, like others, must be faced, and their investigation patiently pursued, without the postulation of special forces whose convenient property it is to meet all emergencies in virtue of their vagueness. If, at least, we are ever to understand the intricate mechanism of the animal machine, it will be granted that we must cease to evade the problems it presents by the use of mere phrases which really explain nothing.
We have seen that amongst the phenomena of response, there is no necessity for the assumption of vital force. They are, on the contrary, physico-chemical phenomena, susceptible of a physical inquiry as definite as any other in inorganic regions.
Physiologists have taught us to read in the response-curves a history of the influence of various external agencies and conditions on the phenomenon of life. By these means we are able to trace the gradual diminution of responsiveness by fatigue, by extremes of heat and cold, its exaltation by stimulants, the arrest of the life-process by poison.
The investigations which have just been describedmay possibly carry us one step further, proving to us that these things are determined, not by the play of an unknowable and arbitrary vital force, but by the working of laws that know no change, acting equally and uniformly throughout the organic and the inorganic worlds.
FOOTNOTES:[21]Verworn,General Physiology, p. 18.
[21]Verworn,General Physiology, p. 18.
[21]Verworn,General Physiology, p. 18.
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