From the morphological point of view he shows one or two stigmata of infantilism: his great height need not be held to disprove this, for gigantism and retardation of sexual development are often in association. In spite of his nineteen years, J. has still a eunuch's voice and a minimum of axillary and pubic hair--in fact, one might say that physically he is thirteen years old, and mentally ten. Or take Mademoiselle R., aged twenty-six: Her intellectual attainments are those of a child of twelve, her age when her first tics made their appearance. Her artlessness and timidity are simply childish, and at the same time she lacks womanly charm and feminine ways. Or again: Young thirteen-year-old M. has been afflicted with tics of face, head, and shoulders for the last three years. Though small, he is well enough built, and has no obvious physical anomaly except an odd admixture of blonde and brown in his hair and eyebrows. His teeth are bad and misplaced, and several of the first dentition persist. There is no sign of pubic or axillary growth. As a general rule he is mild-mannered and docile; sometimes, however, he is irritable, impatient, emotional beyond his years. His degree of intelligence is very fair, but idleness and inconstancy are prominent traits in his character. The ease with which he apprehends is counterbalanced by the readiness with which he forgets, while his reason and judgment are those of a child of seven. The discordance between his actual age and his mental standard is therefore striking enough. Another of our patients is L.: Her intellect is quite up to the average, but the exaggerated importance attached by her parents to her "nervous movements" has only served to intensify her whims. Her eighteen years do not prevent her from revealing signs of mental infantilism in every action of her daily life, but, thanks to suitable treatment, she has been astonishing her father by unheard-of audacities--has she not recently ventured to cross the street alone, and alone to go an errand to a neighbouring shop? X. has a tic of the eyes and has reached the age of forty-eight, yet he told us he was not so much his children's father as their playmate. At the age of fifty-four O. could still remark on his youthfulness of character. The same is true of S., who has attained his thirty-eighth year. It is as arduous a task to define the term "stability of the will," as it is to explain what is meant by physical or mental health. But as it is not essential to preface descriptions of disease with a disquisition on the signs of good health, so anomalies of voluntary activity may surely be noted without a preliminary excursus on normal volition.