expression which is and continues, by reason of its utility, as a sign-language, visual, auditory, or otherwise, as gesture love-calls, etc., may be termed pure expression as distinguished from incidental expression, like blushing, pallor, etc., which exist, not for their significance, though they are significant. Incidental expression includes also the sphere of degraded action. Yet what seems mere degraded action may be true expression, as beckoning, which is an abridgement of the action of pulling one to oneself and of movement towards oneself; but this motion of the hands exists, not for this end, nor as survival, but merely as significant of a desire on the part of the gesturer. In the higher ranges of life we well know the large place played by pure expression as distinguished from incidental expression. It is not necessary to suppose that pure expression consists merely in “voluntary and consciously” employing “means of communication” (Darwin, _Expression of the Emotions_, p. 256); thus, the scream of an infant is equally pure expression, whether the infant employs it knowingly or not as such, for screaming of the young has doubtless arisen and been preserved in natural selection because of its utility as significant. There is then, I think, a group of activities which are not merely incidentally expressive, but originate and exist for expression as a useful thing in the battle of life. But we have not exhausted the principles of expression when we refer to present or past serviceability as an action in general or to service as expression. It is plain that in any activity prompted by any feeling there comes at a certain high intensity a more or less pathologic over-functioning of the organs concerned, with under-functioning of others. Emotion as action stimulator in any high degree always enhances some physiologic function to the depression of others. The blood, for instance, is forcibly withdrawn from various parts to certain specially active parts, and this withdrawal gives rise to an appearance which may be termed a negative expression, as the pallor in fear. Certain other phenomena connected with fear, as change of colour in the hair, cold sweat, and trembling of the muscles, which are mentioned by Darwin as unexplained, are probably due to this negative principle (_Expression of the Emotions in Man and Animals_, New York, 1886, p. 350; but compare pp. 81 and 308, where these disturbances are ascribed to direct action of the nervous system. Darwin does not, however, distinctly state or treat the principle we here mention as a distinct law). As the body is an inter-related system of organs, stimulation to one organ means an effect upon all, excitation of some, depression of others; thus to an acute observer the whole body is symptomatic of every feeling, and, indeed, of every consciousness. In the natural and normal course emotion, to do its work most effectively, implies little or no marked