knowledge of the functions of the higher or primary centres. This was surely to reverse the natural order of inquiry, and to apply the complex and obscure to the interpretation of the simple, instead of ascending by inductive steps to use the simple in order to disentangle the complex. The before-mentioned experiments upon the frog's spinal cord prove that movements seemingly purposive may be purely automatic: why then introduce a new agency, derived from experience of the highest cerebral centres, in order to account for sensori-motor functions which, though more complex than, are of the same character as, those of the spinal cord?

The answer which I conceive it probable may be made is this because the sensory centres are intermediate in structural position and physiological dignity between the spinal and the supreme cerebral centres, and may be expected, while exhibiting reflex functions like those of the spinal cord, to exhibit also the rudiments of functions which attain their special development in the cerebral convolutions. They are more special and complex in structure than the spinal centres, receiving and co-ordinating a greater variety of impressions, and it may be argued that they possess not only some degree of consciousness but the germs of intelligence and volition. At any rate, if it be not so in man, there is evidence that it may be so in some of the lower animals. It would appear that the ant and the bee, which have no higher nervous centres than sensory ganglia, and in which the functions of these centres reach a remarkable perfection, are not simply organised machines that operate with unvarying regularity and are destitute of any power of shaping their acts to new experiences; on the contrary, observation shows that these creatures do sometimes discover in their actions indications of a sensibility to strange experiences and of corresponding adaptations. of movements. Take Huber's account of the humble

bees which he put under a bell-glass along with a comb which was of such a shape as not to be capable of standing steadily. Two or three of the bees got upon the comb, and, stretching themselves over its edge with their heads downwards, fixed their fore-feet on the table, so as to make themselves props and to prevent the comb from falling. When they were tired, others took their places, and the series of reliefs went on for nearly three days, until the bees had prepared sufficient wax to build pillars of support. Moreover, when the first pillars were displaced, they had recourse to the same operations in order to rebuild them. We could scarcely have a more striking instance of an apparent adaptation of means to an end according to varying circumstances. And I know not how those who would attribute such appropriate action to instinct can distinguish it from understanding, even if it be assumed that similar experiences must at some time have occurred to the race of bees. After all, it is only

a manifestation of a power of adapting acts to circumstances by which we must suppose, and Mr. Darwin has shown it to be probable, that bees have gradually acquired their wonderful instincts, and which at bottom is a property of nervous tissue, if not of organic substance.* The power is evidently of a rudimentary kind in bees, and must remain so in creatures that have not the higher nerve-centres in which sensations are combined into ideas, perceptions of the relations of things thus acquired, and acts purposely shaped in consequence to

* Mr. Wallace has broached and upheld the opinion that bees and ants do not act without instruction and blindly. He thinks that birds build their nests, as men build their houses, from observation, memory, and imitation, using the material which each kind can most readily obtain, and building in situations most congenial

s habits. Indeed, he asserts that "the peculiar notes of birds are acquired by imitation, as surely as a child learns English or French, not by instinct, but by hearing the language spoken by its parents."

or not.

accomplish ends whether the circumstances are changed But because bees have possessed, and still possess, this rudimentary understanding, which differs in simplicity rather than in kind from human understand ing, it does not follow that the sensory ganglia of man are endowed with similar rudimentary functions. On the contrary, it might be argued that as higher nervous centres are differentiated in the course of evolution, functions are localised in them which were more generally diffused in the lower animals, not otherwise than as the fore limbs in man, which in the ape and some other animals serve both for grasping and walking, are specialised in structure and function as prehensile organs. In the absence then of positive evidence of intelligence and voluntary power in the sensory ganglia of man, it is a scarcely warrantable assumption to endow them even with the rudiments of these functions.*

But it is impossible to feel an equal assurance when the question is made one not of the existence of intelligence and will, but of the existence of consciousness in the sensory centres. Three considerations occur to the mind in reference to this question. The first is, that in the higher animals properties are localised in particular organs which in lower animals are diffused throughout the organism; and while this may be used as an argument in favour of the supposition that consciousness is entirely limited to the cerebral hemispheres in man, it certainly does not exclude the possibility of its existence in the sensory centres. For it may well be

* Unless, as I have already pointed out, we take all heart of meaning out of the word volition, by calling the adaptive power of organic element by the name. After referring to Spallanzani's observations on polypes, Prochaska says-" From these and other facts it is manifest that these infusory animalcules feel, and have volition, and possess the character of the true animal ; consequently, they are endowed with a sentient and volitional principle, however destitute they may be of a nervous system."

that organs which are only a little lower in dignity than the supreme cerebral centres, which are essential to the development of their function, and which are in such intimate functional relation with them throughout life that a functional separation appears to be pure abstraction, do possess that property which is most highly, but not exclusively, developed in the higher centres.

Secondly, it admits of no doubt that consciousness is not a constant quantity, but that there are gradations of consciousness from its most vivid manifestations through stages of lessening subconsciousness down to actual unconsciousness. It may well be then that the sensory centres possess it in a less degree than the centres above them. The plain proof that they do possess it, some might argue, is that we feel pain when we are hurt; and that the pain is felt in a sensory centre is further proved by experiments on animals which cry out when they are hurt, after their cerebral hemispheres have been removed. The argument, however, is by no means conclusive. In the first place, we have no proof that the animals feel the pain; all we know is that they cry out as if they felt it; and if we may trust our inferences from other experiments on animals and from observations of men under chloroform and in comatose states, we must admit that the cry may be purely a reflex act. In the second place, it is doubtful whether we ever are conscious of a sensation without perceiving, whether in fact we can have consciousness of a pure sensation: when we say we feel it, we feel it in a particular part of the body; and what is that but to perform internally a sensori-motor act and to recognise more or less clearly its where, in other words, to perceive it according to forms of space? We infer the existence of simple sensations out of which ideas are formed by a mental synthesis, but it is a question whether a consciousness of them does not imply that our higher cerebral centres have come into play

and that we are exercising perception. To adopt the metaphysical theory which has been broached by some psychologists, that the organism in its relation to perception belongs neither to the ego nor to the non-ego, but occupies an intermediate position between them, is to dupe ourselves with vain words, which do not carry us a step farther towards an understanding of the facts; whether we accept it or not, the problem remains just what it was.

The third consideration is, that although the cerebral centres, as representing the highest and most complex co-ordination of functions, are undoubtedly the seat of clear consciousness, of the individual's consciousness as an ego, the sensory centres may still be conscious after a fashion of their own, and may send their unperceived contributions to make up the sum of that general consciousness which is the consciousness of the ego. This theory of an unconscious consciousness I have already discussed, and I need say no more about it now. The conclusion of the whole matter is, that while many plausible arguments may be brought forward on the one side and on the other, we have not the data to warrant us in deciding positively whether consciousness, or, if any, what sort of consciousness, is a property of the sensory ganglia, and that the question must for the present remain open.

One reflection we may profitably educe from the discussion, before passing from the subject-namely, how artificial and unwarranted is the absolute division which is made between the conscious and the unconscious, between psychology and physiology. Notwithstanding that nature everywhere reveals the law of continuity, and. notwithstanding that the progress of knowledge has been a history of the breaking down of arbitrary divisions in knowledge where none existed in nature, we still go on to make nature conform to our divisions, and as soon as