sure the material was squeezed upward to higher levels, following lines of least resistance, and consolidated at greater or less. depths beneath the surface. This upward movement was probably coincident with the crustal movements that elevated the entire Absaroka Range. The line of Ishawooa intrusives marks the trend of one such upward movement of molten magma, which for the most part congealed without finding egress to the surface. That a portion of the magma may have been pushed upward through fissures and vents and discharged as surface flows of andesite is possible, but of such flows, if they existed, no positive evidence remains.

Conditions somewhat similar to those found in the Absarokas are described by Professor Adolph Stelzner as occurring in the Andes of Argentina. He describes granites, diorties and syenites as penetrating the andesitic tuffs and lavas of Tertiary age, and as cooling under a heavy load of superimposed material. He does not regard these massive crystalline bodies as conduits of volcanoes, but as large stocks formed independently of such vents. He refers to them as taking part in the great orogenic uplift which elevated the Cordillera of South America, an uplift which began in Jurassic time, lasted through the Mesozoic, and continued through the greater part of the Tertiary.

In the discussions of volcanic phenomena found throughout geological literature, circular vents of great depth seem to be regarded as indispensable and are supposed to furnish an open door for the molten magmas, permitting them to take a straight shoot from the eternal depths to daylight. In this way geologists certainly avoid many perplexing physical problems which confront us in the case of stocks and laccoliths penetrating sedimentary rocks and stopping far short of the surface. In speaking of areas of igneous rocks, one almost hesitates to use the term laccoliths, so universally is

it referred to in its relation to sedimentary rocks. For my part, it seems far more reasonable to look for such intrusive bodies in areas of igneous rock than in regions of sedimentation. That large intrusive bodies came to a standstill without any surficial manifestations, in the Absarokas, is, I think, fairly well determined.

Two years ago it was my good fortune to cross the Cascade Range at a number of localities and to climb far above timber line the slopes of Mount Rainier, in Washington; Mount Hood, in Oregon, and Mount Shasta, in California. From these commanding points comprehensive panoramic views were obtained over a broad field of igneous rock. Majestic and impressive as are these volcanoes, and grand in their isolation, I could but feel that back of them all lay earlier chapters in the Tertiary history of volcanic energy on the Pacific side of the Cordillera; that these powerful volcanoes were but a late expression of the intensity of the eruptive energy, and that still earlier volcanic masses had in some way taken part in the orogenic disturbances of an earlier Tertiary time. So, on the east side of the great Cordillera, the early Tertiary fires long since ceased to glow in the Absarokas, and the center of volcanic energy moved westward and built up on different lines the broad rhyolite plateau of the Yellowstone Park, a plateau strongly contrasted with the Absarokas in the almost entire absence of breccias. The work of such investigators as Emmons and Cross in Colorado and Weed and Pirsson in Montana is slowly but surely solving the problems of the post-Cretaceous uplift in the northern Cordillera, and, it will, I think, finally be shown that the crystalline rocks consolidated below the surface have played an important part in bringing about the Cordilleran revolution.

On a bright crisp autumnal day in 1897 I left the Absarokas by the way of that

most interesting of valleys, Clark's Fork of the Yellowstone, still impressed with the many unsolved problems connected with the geology of the range. I at first visited the region in the expectation of finding a partially submerged range of Paleozoic and Mesozoic sediments. If ever such range existed, it had completely disappeared by profound subsidence. I then looked for the roots of some powerful dominating volcano which had been the source of the varying breccias, but this also I failed to discover. In its stead, if I interpret the facts correctly, I found penetrating the breccias the towering domes and pinnacles of granular and porphyritic rocks, which in some fardistant day, when denudation has removed a greater part of the overlying mass, may be found to form one connected body which erosion has already so far laid bare as to indicate that they all form a part of one broad complex of coarsely crystalline rock of early Tertiary age.

ARNOLD HAGUE.

U. S. GEOLOGICAL SURVEY, WASHINGTON, D. C.

THE PHYSIOLOGICAL BASIS OF MENTAL

LIFE.*

If we demand a physiological process corresponding to every possible variation of the content of consciousness the structure of

the brain seems far too uniform to furnish The

a sufficient manifoldness of functions.

mere number of elements cannot be decisive; if they are all functionally coordinated they can offer merely the basis for coordinated psychical functions. If we have psychical functions of different orders it would not help us even if we had some millions more of the uniform elements. It would be useless to deny that here exists a great difficulty for our present psychology ; the only question is whether this difficulty really opposes the demands and supposi*Read before the joint meeting of the Psychological Association and the Physiological Society.

tions of psychophysical parallelism or whether it means that the usual theories of to-day are inadequate and must be improved. It seems to me that the latter is the case, and that hypotheses can be constructed by which all demands of psychology can be satisfied without the usual sacrifice of consistency. The situation is the following:

The whole scheme of the physiologists operates to-day in a manifoldness of two dimensions: they think the conscious phenomena as dependent upon brain excitements which can vary firstly with regard to their localities and secondly with regard to their quantitative amount. These two variations then correspond to the quality of the mental element and to its intensity. In the acoustical center, for instance, the different pitch of the tone sensations corresponds to locally different ganglion cells, the different intensities of the same tone sensation to the quantity of the excitement. Association fibers whose functions are not directly accompanied by conscious experiences connect these millions of psychophysical elementary centers in a way which is imagined on the model of the peripheral nerve. No serious attempt has been made to transcend this simple scheme. Certainly recent discussions have brought many propositions to replace the simple physiological association fiber which connects the psychophysical centers by more complicated systems-theories, for instance, in regard to the opening and closing of the connecting paths or in regard to special association centers or special mediating cell groups-but these and others stick to the old principle that the final psychophysical process corresponds to the strength and locality of a sensory stimulation or of its equivalent reproduction, whatever may have brought about and combined the excitements.

It is true that it has been sometimes suggested that the same ganglion cell may go

over also into qualitatively different states of excitement, and thus allow an unlimited manifoldness of new psychophysical variations. But it is clear that to accept such an hypothesis means to give up all the advantages of brain localization. The complicatedness of the cell would be in itself sufficient to give ground to the idea that its molecules may reach some millions of different local combinations, and if every new combination corresponds to a sensation all the tones and colors and smells and many other things may go on in one cell. But, then, it is, of course, our duty to explain those connections and successions of different states in one cell, and that would lead to thinking the cell itself as constructed with millions of paths just like a miniature brain; in short, all the difficulties would be transplanted into the unknown structure of the cell. If we, on the other hand, do not enter into such speculations the acceptance of qualitive changes in the cell would bring us to the same point as if we were satisfied to speak of qualitative changes of the brain in general. It would not solve the problem, but merely ignore it, and, therefore, such an additional hypothesis cannot have weight.

The only theory which brings in a really new factor is the theory of innervation feelings. This well-known theory claims. that one special group of conscious facts, namely, the feelings of effort and impulse, are not sensations and, therefore, not parallel to the sensory excitements, but are activities of consciousness and parallel to the physiological innervation of a central motor path. At this point, of course, comes in at once the opposition of the philosophical claim that every psychical fact must be a content of consciousness, and made up of sensations, that is, of possible elements of idea, to become describable and explainable at all. The so-called active consciousness, the philosopher must hold, has nothing to do with an activity of the

consciousness itself, as consciousness means, from the psychological standpoint, only the kind of existence of psychical objects. It cannot do anything, it cannot have different degrees and functions, it only becomes conscious of its contents, and all variations are variations of the content, which must be analyzed without remainder into elements which are theoretically coördinated with the elements of ideas, that is, with the sensations, while consciousness is only the general condition for their existence. But also the empirical analysis and experiment of the practical psychologist are in this case in the greatest harmony with such philosophical claims and opposed to the innervation theory. The psychologist can show empirically that this so-called feeling of effort is merely a group of sensations like other sensations, reproduced joint and muscle sensations which precede the action and have the rôle of representing the impulse merely on account of the fact that their anticipation makes inhibitory associations still possible. It would thus from this point of view also be illogical to think the psychophysical basis of these sensations different in principle from that of other sensations. If the other sensations are accompaniments of sensory excitements in the brain the feelings of impulse cannot claim an exceptional position.

But are quality and intensity really the only differences between the given sensations? Can the whole manifoldness of the content of consciousness really be determined by variations in these two directions only? Certainly not; the sensations can vary even when quality and intensity remain constant. As an illustration we may think, for instance, of one variation which is clearly not to be compared with a change in kind and strength of the sensation; namely, the variation of vividness. Vividness is not identical with intensity; the vivid impression of a weak sound and the

unvivid impression of a strong sound are in no way interchangeable. If the ticking of the clock in my room becomes less and less vivid for me the more I become absorbed in my work, till it finally disappears, it cannot be compared with the experience which results when the clock to which I give my full attention is brought farther and farther away. The white impression, when it loses vividness, does not become gray and finally black, nor the large size small, nor the hot lukewarm. Vividness is a third dimension in the system of psychical elements, and the psychologist who postulates complete parallelism has the right to demand that the physiologist show the corresponding process. There are other sides of the sensation for which the same is true; they share with vividness the more subjective character of the variation, as, for instance, the feeling tone of the sensation or its pastness and presentness. Other variations bring such subjective factors into the complexes of sensations without a possibility of understanding them from the combination of different kinds only; for instance, the subjective shade of ideas we believe or the abstractedness of ideas in logical thoughts. In short, the sensations and their combinations show besides kind, strength and vividness still other variations which may best be called the values of the sensations and of their complexes. Is the typical theory of modern physiological psychology, which, as we have seen, operates merely with the local differences of the cells and the quantitative differences of their excitement, ever able to find physiological variations which correspond to the vividness and to the values of the sensations?

An examination without prejudice must necessarily deny this question. Here lies the deeper spring for the latent opposition which the psychophysiological claims find in modern psychology. Here are facts, the

opponents say, which find no physiological counterpart, and we must, therefore, acknowledge the existence of psychological processes which have nothing to do with the physiological machinery. The vividness, for instance, is fully explained if we accept the view that the brain determines the kind and strength of the sensation, while a physiologically independent subject turns the attention more or less to the sensation. The more this attention acts the more vivid the sensation; in a similar way the subjective acts would determine the feeling tone of the sensation by selection or rejection, and so on. While the usual theory reduces all to the mere association of locally separated excitements, such a theory thus emphasizes the view that the physiologically determined functions must be supplemented by an apperceiving subject which takes attitudes. We may call the one the association theory, the other the apperception theory. We have acknowledged that the association theory is insufficient to solve the whole problem, but it is hardly necessary to emphasize that the apperception theory seeks the solution from the start in a logically impossible direction, and is thus still more mistaken than the association theory.

The apperception theory, whatever its special label and make-up may be, does not see that the renunciation of a physiological basis for every psychical fact means resigning the causal explanation altogether, as psychical facts as such cannot be linked directly by causality, and that resigning the causal aspect means giving up the only point of view which comes in question for the psychologist. If those apperceptive functions are seriously conceived without physiological basis they represent a manifoldness which can be linked merely by the teleological categories of the practical life, and we sink back to the subjectifying view which controls the reality of life, but which