The movements of the alimentary canal, both gross and minute, have been studied with much success. It is beginning to be recognized at last that where contractile tissue is there is movement! The Roentgen rays have revealed some of the complex movements of the gut, 18 Years ago, and now the finer movements, e.g., of the villi, remain to be described. Nearly five years ago I called attention to their move ment and to one of their possible ulterior absorptive functions: °The 4,000,000 villi of the intestine, rich in smooth muscle and sympa thetic nerves as well as in epithelium, probably adapt the blood's content of the nutritive lipoids and proteins to the varying immediate needs of the nerve-cells, and may besides send inward sympathetic influences which, fusing, possibly in the brain, become euphoric.° Dietetics has made strides, especially in the direction of applied economic physiology. The old matter of doubt as to the safe-minimum of protein has not been clarified to everyone's satis faction.
The integrating nervous system has become better known in certain of its functions. The sensory side of the autonomic (itself relatively a recent "discovery")) has been developed as Remak's fibres, thus laying more of the physical basis of the subconscious aspects of mind. The cerebral cortex has revealed some of its func tions on a basis of psychomotion, especially in the way of restraint. Work has been done on the physiology (vasomotion and keinesthesi ology mostly) of sleep. The reflexes have been studied in many directions, practical and theo retic. The senses have been investigated in new ways, on one hand highly technical and on the other practical and popular, a new series of books on the senses helping the latter purpose. Vasomotion has been getting on to a gratifying extent.
The neuro-musculo glandular system, mechanism of efficiency, has received much at tention, especially in England and in some of the physical-education schools of America. The all-or-none principle has been of use in under standing many things in regard to skill. The relations of physiology to exercise has been developed in many directions; and those of sat isfaction to the dynamic aspects of work— the so-called "stheneuphoric index') or energy-joy ratio. The rehabilitation of one hellwar crip pled and shocked is sure to give the psycho logical physiology of skill a chance to develop far in theory as well as in practice.
Dental physiology has gone on, largely in the directions of electrical and pathological and prosthetic physiology.
The skin has been revealing some of its hid den mysteries, and proves to be an organ of pre-eminent general importance to the indi vidual. If I may again repeat part of an article
— summary of nearly five years ago: The integrated epicritic impulses (from the skin and mucosm) appear to have predominance in human physiologic euphoria, two possible means of stimulation being evaporation and oxidation.
A list of the more or less influential elements of the skin would include the complex vaso motor mechanism; the arrectores pilorum mus cles; afferent sympathetic dendrites, the pecu liarly efficient epidermis, sweat glands, seba ceous glands; Meissner's corpuscles, the ter minal cylinders of Ruffini, tactile menisci, the nerve-rings of Bonnet ( ?), Vater-Pacinian cor puscles, free nerve-endings, heat-receptors, cold receptors, pain-receptors, pleasure-receptors, and possibly tickle-receptors.
Air that is dead (i.e., not moving) ; humid and too warm; humid and too cold; or lacking in oxygen is a chief occasion of orTanic dys phoria. Physiologically these conditions are lacks,— lack of movement over the skin, lack of the optimum temperature, lack of dryness (evaporation so being lessened), and lack of dermal oxygen, possible reflex determinant in part of pulmonary respiration.
Arterial tension has been actively studied in many places and is about to reach important practical conclusions as we learn more and more of the intricate controls of vasomotion. A new "continuous," method has been devised for the study and record (hemobarogram) of the ever-varying blood-pressures termed sys tolic and diastolic, respectively. From the Pro ceedings of the American Psychological Asso ciation (December 1916) the following slightly modified excerpts may be added to indicate the status of one phase of the physiology of blood pressure at that time. Nine or ten thousand measurements sanction these tentative proposi tions, as the hemobarograms show: Arterial stuffing and constriction are very active and variable in all persons. Peripheral arterial tension is by far the most sensitive and easiest index of vasomotor rearrangement correlate to activity mental or bodily. The doubleness of blood-pressure measurement ("systolic° and makes possible a partially differential index of activities : The "systolic° tension represents especially the ever-changing output of the left heart, which latter is quickly variable in size (Gesell) as well as in the frequency of its contraction. The diastolic tension is more dependent on the autonomic vasomotion, direct and reciprocal. Thus the systolic variations are more directly mental, and the diastolic more somatic and vegetative.