both for mediating the execution of acts of will and for the production of sensations is the semi-fluid consistency of the whole mass, which furthers the displacement and rotation of the molecules, and the polar nature of the individual molecule, which has a high degree of chemical organisation of matter for its condition. The former is equally well shown by the protoplasm of lower animals and plants. In every cell there is to be made out at least a fluid content and a solid wall, commonly also a nucleus; both the nucleus, or at any rate its environment, as well as the boundary of wall and content, frequently, however, the whole content of the cell, exhibit this semi-fluid consistency of high chemical organisation, from which physical and chemical elements one may conclude with probability to a polar constitution of the molecules, if also in a less. degree than in nerves, and of the central ganglion cells, which likewise consist of nucleus, wall, and content, especially if one takes note of the phenomena of contraction of all animal and vegetable protoplasm after electrical stimulation. These conditions, however, recur in all properly living parts of higher plants, probably even in heightened forms, since the chemical organisation of matter manifestly increases in higher organisms, but in no case sinks. But quite specially vegetable protoplasm, which, as we have seen, brings to pass the quick reflex movements of the higher plants, shows apparently a perfect identity with the protoplasm of the Protista and lowest animals, as is proved by the same behaviour with respect to the most different stimuli and narcotics. This protoplasm has, however, also in higher animals a very wide distribution ; and if attention was at first turned to its vital action by those examples, where its movements achieve results which become visible and startling even to the naked eye, at the present moment vegetable physiology already studies with zeal the movements of protoplasm going on within the cells on the irritation of light, heat, and other stimuli, which manifestly stand in the closest relation to the life

and propagation of the cells.1 There is thus quite certainly no ground for the assertion that the sensation and the consciousness of higher plants stand below that of the lowest plants and animals; on the contrary, we may presume that, although the total and partial mobility of plants of higher forms decreases in conformity with their vital conditions, the sensations, at least in certain privileged parts, rank above that of the lower plants.

The lower we descend in the animal scale, the more does the importance of the sensations related to digestion and the genital region increase in comparison with those arising from outer stimuli. In plants where the surface is more and more secluded from the insignificant external stimuli, this augmentation will go still further. For the plant, the outer world, except light and the chemical constitution of the atmosphere, is continually losing all interest, and we only owe to special cases the knowledge that also higher plants take notice of certain events which obtain for them importance, e.g., the plants which capture insects, of stimuli which affect the leaves, the climbers of supports, &c.

After the foregoing it will no longer surprise us if we attribute to plants a sensation (and of course conscious sensation) of the stimuli on which they, whether reflectorially or instinctively, react; if we assert that the

1 As in lower animals (e.g., Amobæ), so also in the protoplasm of living vegetable cells, there are to be distinguished a state of activity and another of perfect rest, which may alternate with one another even several times. Although both states uniformly belong to life, yet only in the former does there appear to be present a distinct sensibility, whereas there is in the latter a lowering of irritability, which resembles the anesthesia of protoplasm brought about by narcotic vapours, and perhaps forms an analogue of animal sleep, or still

better of hibernation. As certain infusoria, after a period of active vitality, enter upon a period of incrustation, so also do many vegetable cells that at maturity surround themselves with a thicker cell-wall, which cell-wall may even remain after their death (e.g., ligneous cells). The acme of sensibility in every vegetable cell one must therefore only seek in a particular, sometimes perhaps very short, epoch of their life, which forms the culminating point of their vital activity, and accordingly for the most part falls into their youthful period.

Oscillatoria as well as the polyp feels light if it wanders towards the illuminated part of its vessel, and that just in the same way the vine-leaf feels the light, to which it endeavours by all means to turn its right side, and every flower feels the light, to which it on expanding turns its tiny head. We maintain that the leaf of the Dionœa and of the Mimosa pudica feels the struggling of the insect before it reacts on this sensation by folding up; for it lies indeed in the notion of reflex action, as a psychical reaction, that a psychical perception must precede the same. This is, however, conscious sensation. We further maintain that the plant has a sensation of the physical events of the organisation which answer to animal digestion and of sexual life; that the latter especially takes place in parts where the higher vitality of vegetable existence is concentrated, where the plastic activity during flowering time effects no longer compounding, but decompounding chemical processes (as the inhaling of oxygen and exhaling of carbonic acid of the flowers proves); whence it follows that here the formative forces have withdrawn from material construction into a certain animal-like internalisation, and become disposable for more receptive processes. That the content of this consciousness must always be still very poor, much poorer, e.g., than that of the wretchedest worm, hardly admits of doubt; for whence should wealth and definiteness come, such as is afforded the animals through the lowest sense-organs?

We have thus, in fact, found consciousness in the plant. But now how far can a UNITY of consciousness exist in the plant?-We have seen that the unity of the consciousness of two ideas or sensations depends on the possibility of comparison, and this on the presence of a sufficient communication between the two places producing sensation. The question then is this: Does such a communication exist in the plant? Already in the animal the converse between different nerve-centres, although mediated by nerve-cords, was exceedingly deficient

A

and the unity of consciousness in fact only extant for very energetic excitements. The velocity of propagation of the nerve-current in man, according to Helmholtz, amounts to about a hundred feet in a second; that in the Mimosa pudica, as before mentioned, only to a few millimeters. One can draw from these velocities a tolerable conclusion as to the resistances to conduction, and accordingly to the disturbances and changes of the propagated results. It is possible that the spiral vessels serve such. purposes of communication, but it is not proven. At all events, with regard to the unity of consciousness of two neighbouring anthers, the connection must be infinitely weaker than with that of brain and ganglia in man. sufficiently faithful and strong conduction will always only be able to exist between the parts lying quite near to one another. I would not affirm that one is at liberty to speak of the indivisible consciousness of a flower,-hardly perhaps of that of a stamen. The plant does not, however, need such a unity of consciousness as the animal; it needs to institute no comparisons, and does not need to reflect on its actions. It needs only surrender itself to the single sensations, and let the same serve as motives for the incursions of the Unconscious. Then have these fulfilled their purpose; and this is accomplished just as well by sensations with separate consciousness as by those with one indivisible consciousness.

V.

MATTER AS WILL AND IDEA.

PHYSICAL Science is concerned with three inter-connected objects: laws, forces, and matter. This division is entirely deserving of approval, for it summarily embraces different groups of phenomena under single points of view and facilitates expression. The question now is, whether these three are really of different nature; or whether, strictly speaking, they are only one, which, looked at merely from different points of view, appears in three different modes? Of the laws this may well be allowed without discussion, for it is obvious that they are not existences hovering in the air, but mere abstractions of forces and substances. Only because this force and this matter are so and so, only on that account do they act in a particular manner; and as often as we meet with such a force, we must find it acting in just such a way. This constancy of the soacting, however, it is which we call Law. This relation is also pretty generally acknowledged, and we hear, in fact, materialists always speak of force and matter as their principia, as something which of course includes laws. We have in C. Chap. ii. defended Materialism, so far as it maintains organised matter to be the conditio sine qua non of conscious mental activity; we have in the preceding inquiries established an unconscious psychical principle as superior to matter, and thereby already shown the one-sidedness of that Materialism which knows no other than material principles. We have now arrived at the point where we must occupy ourselves with that,