Similar results were secured with the monkey, where the precentral gyrus, the so-called motor cortex, of one hemisphere and then another had been removed. The monkey was trained to open problem boxes with one hand. This he was able to do with the other hand when he had recovered from the paralysis. It was a case of almost perfect transfer.

Here we have evidence of the utilization of neural paths in the performance of a learned reaction which were not activated during the course of learning. The drainage theory is not acceptable. Irridation of impulses to symmetrically placed spinal neurones might account for the results but I have records of other cases where the head or leg was substituted for the arm rendered useless by operation, and where, consequently, irridiation cannot explain the transfer of the habit to the unused organ. An alternative theory is not possible in the present state of the science of neurophysiology. . . . The phenomena of equipotentiality of function of cerebral areas, of vicarious function. without definite localization, of mass action, of central ganglia, of temporal variation in function, and the accumulating mass of evidence which indicates that in the intact organism every reaction is an expression of the total activity of the central nervous system, all are difficult to harmonize with a system of anatomically restricted reflex paths defined by varying degrees of synaptic resistance. Work upon the 'all or nothing' character of conduc tion and the refractory period of nerves suggests that the rate at which the neurone may transmit successive impulses is at least as important in determining the direction of conduction as the degree of synaptic resistance.

8. New Conceptions of Cerebral Functions

[FRANZ, Shepherd Ivory, "Conceptions of Cerebral Functions," Psychological Review, November, 1923, Vol. 30, pp. 438-446.]

Franz cites some cases of behavior that make it necessary for us to revise the orthodox view of localization of brain functions. He finds evidence that many parts of the brain function at one time, and consequently that we utilize the cerebrum as a whole in our adjustments, rather than some particular portion of a motor or sensory area.

Many parts of the brain function at one time, and so widely separated are those parts that we have the right to say that the brain functions as a whole.

This shows clearly the inadequacy of the phrenological or faculty view as an explanation, and the necessity for a more adequate general statement. It also means that the distinction should be drawn between a general explanation and those deductions that have immediately practical applications. And, furthermore, it means that however much our practical needs are met by an explanation, an explanation is not more than a verbal summary, to be added to or subtracted from as newer practice evolves. . ..

But the phrenological view, leaving out the conception of storage of ideas, must be understood in its proper place as a diagnostic approximation, and the original view of Flourens is the more general view which we must also modify in the light of our accumulated knowledge. . . . It is, I believe, the modified form of the belief in the utilization of the cerebrum as a whole in our adjustments-mental operations if you wish to use the term that is most stimulating and more inclusive.

9. The Autonomic Nervous System

[CANNON, W. B., Bodily Changes in Pain, Hunger, Fear, and Rage, pp. 22-38; 63-64. New York, D. Appleton & Co., 1922.]

Dr. Cannon, noted physiologist at Harvard University, has done some real pioneering in the study of emotions and their relation to the autonomic nervous system. As in most pioneer works, some of the conclusions should be accepted tentatively until further experimental evidence is available. The entire book from which our selection is taken is well worth reading. It should be kept in mind that much work has been done in this field since Cannon wrote his book.

The skeletal muscles receive their nerve supply direct from the central nervous system. The neurones distributed to these muscles are parts of neurones whose cell bodies lie within the brain or spinal cord. The glands and smooth muscles of the viscera, on the contrary, are, so far as is now known, never innervated directly from the central nervous system. The neurones reaching out from the brain or spinal cord never come into immediate relation with the gland or smooth-muscle cells; there are always interposed between the cerebro-spinal neurones and the viscera extra neurones whose bodies and processes lie wholly outside the central nervous system. . . . I have suggested that possibly these outlying neurones acted as 'transformer,'

modifying the impulses received from the central source (impulses suited to call forth the quick responses of skeletal muscle), and adapting these impulses to the peculiar, more slowly-acting tissues, the secreting cells and visceral muscles, to which they are distributed.

The outlying neurones typically have their cell bodies grouped in ganglia which, in the trunk region, lie along either side of the spinal cord and in the head region and in the pelvic part of the abdominal cavity are disposed near the organs which the neurones supply. In some instances these neurones lie wholly within the structure which they innervate. In other instances the fibers passing out from the ganglia-the so-called 'post ganglionic fibers'-may traverse long distances before reaching their destination. The innervation of blood vessels in the foot by neurones whose cell bodies are in the lower trunk region is an example of this extensive distribution of the fibers.

As suggested above, the outlying neurones are connected with the brain and spinal cord by neurones whose cell bodies lie within the central nervous organs. These connecting neurones do not pass out in an uninterrupted series all along the cerebrospinal axis. Where the nerves pass out from the spinal cord to the fore and hind limbs, fibers are not given off to the ganglia. Thus these connecting or 'preganglionic' fibers are separated into three divisions. In front of the nerve roots for the fore limbs is the head or cranial division; between the nerve roots for the fore limbs and those for the hind limbs is the trunk division (or thoracico-lumbar division, or, in the older terminology, the 'sympathetic system'); and after the nerve roots for the hind. limbs the sacral division.

This system of outlying neurones, with postganglionic fibers innervating the viscera, and with preganglionic fibers reaching out to them from the cerebrospinal system, has been called by Langley, to whom we are indebted for most of our knowledge of its organization, the autonomic nervous system. This term indicates that the structures which the system supplies are not subject to voluntary control, but operate to a large degree independently. As we have seen, a highly potent mode of influencing these structures is through conditions of pain and emotional excitement. The parts of the autonomic systemthe cranial, the sympathetic, and the sacral-have a number of peculiarities which are of prime importance in accounting for the bodily manifestations of such affective states.

The fibers of the sympathetic division differ from those of the

other two divisions in being distributed through the body very widely. They go to the eyes, causing dilation of the pupils. They go to the heart and, when stimulated, they cause it to beat rapidly. They carry impulses to arteries and arterioles of the skin, the abdominal viscera, and other parts, keeping the smooth muscles of the vessel walls in a state of slight contraction or tone, and thus serving to maintain an arterial pressure sufficiently high to meet sudden demands in any special region; or, in times of special discharge of impulses, to increase the tone and thus also the arterial pressure. They are distributed extensively to the smooth muscle attached to the hairs; and when they cause this muscle to contract, the hairs are erected. They go to sweat glands, causing the outpouring of sweat. These fibers pass also to the entire length of the gastro-intestinal canal. And the inhibition of digestive activity which, as we have learned, occurs in pain and emotional states, is due to impulses which are conducted outward by the splanchnic nerves— the preganglionic fibers that reach to the great ganglia in the upper abdomen-and thence are spread by postganglionic fibers all along the gut. They innervate likewise the genito-urinary tracts, causing a contraction of the smooth muscle of the internal genital organs, and usually relaxation of the bladder. Finally they affect the liver, releasing the storage of material there in a manner which may be of great service to the body in time of need. The extensiveness of the distribution of the fibers of the sympathetic division is one of its most prominent characteristics. .

The cranial and sacral autonomic divisions differ from the sympathetic in having only restricted distribution. The third cranial nerves deliver impulses from the brain to ganglia in which lie the cell bodies of neurones innervating smooth muscle only in the front of the eyes. The vagus nerves are distributed to the lungs, heart, stomach, and small intestine. . . . The outlying neurones in the last three of these organs lie within the organs themselves.

In this sacral division the preganglionic fibers pass out from the spinal cord to ganglia lying in close proximity to the distal colon, the bladder, and the external genitals. And the postganglionic fibers deliver the nerve impulses only to the near-by organs. Besides these innervations the cranial and sacral divisions supply individual arteries with 'dilator nerves'-nerves causing relaxation of the particular vessels.

The cranial autonomic, represented by the vagus nerves, is

the part of the visceral nervous system concerned in the psychic secretion of the gastric juice. Pavlov showed that when these nerves are severed psychic secretion is abolished. The cranial nerves to the salivary glands are similarly the agents for psychic secretion in these organs, and are known to cause also dilation of the arteries supplying the glands, so that during activity the glands receive a more abundant flow of blood.

Great emotion, such as is accompanied by nervous discharges via the sympathetic division, may also be accompanied by discharges via the sacral fibers. The involuntary voiding of the bladder and lower gut at times of violent mental stress is well known. Veterans of wars testify that just before the beginning of a battle many of the men have had to retire temporarily from the firing line. And the power of sights and smells and libidinous thoughts to disturb the regions controlled by the nervi erigentes proves that this part of the autonomic system also has its peculiar affective states.

Lying anterior to each kidney is a small body-the adrenal gland. It is composed of an external portion or cortex, and a central portion or medulla. From the medulla can be extracted a substance, called variously suprarenin, adrenin, epinephrin, or 'adrenalin,' which, in extraordinarily minute amounts, affect the structures innervated by the sympathetic division of the autonomic system precisely as if they were receiving nervous impulses. For example, when adrenin is injected into the blood it will cause pupils to dilate, hairs to stand erect, blood vessels to be constricted, the activities of the alimentary canal to be inhibited, and sugar to be liberated from the liver. These effects are not produced by action of the substance on the central nervous system, but by direct action on the organ itself. And the effects occur even after the structures have been removed from the body and kept alive artificially.

The adrenals are glands of internal secretion, i.e., like the thyroid, parathyroid, and pituitary glands, for example; they have no connection with the surface of the body, and they give out into the blood the material they elaborate.

The foregoing brief sketch of the organization of the autonomic system brings out a number of points that should be of importance as bearing on the nature of the emotions which manifest themselves in the operation of this system. Thus it is highly probable that the sympathetic division, because arranged for diffuse discharge, is likely to be brought into activity as a whole, whereas the sacral and cranial divisions, arranged for