＂The study of mind was advanced as remarkably during the nineteenth century as any of its sister sciences. Here, as elsewhere, observation grew keener, new instrumental tests were adopted, and interpretation became more sagacious. A fact as commonplace as the length of human babyhood, when it came under the eye of John Fiske, went far to explain the foundations of the family, and how it came about that primitive man, to whom much was given, so added to his gifts that at last the gulf betwixt him and his next of kin became all but infinite. Of the new study of children, which owes a weighty debt to Darwin and Preyer, Professor Sully is aworthy exponent. In this volume he has something to say of the deepest interest to parents, to all students of the early unfolding of human faculty. In the inquiry of Mr. Galton regarding Twins we have a sterling example of the statistical method. Who shall call that method dry and unfruitful after he reads what it brought to this patient and discerning investigator? If it be assumed that there is nothing in the mind that has not been in the senses, it becomes a question of importance, How may sight, the noblest of the senses, come to its best estate? Has it been affected for good or harm by civilized life? This question is discussed with shrewd humour by Mr. Hudson in his chapter on the sight of savages. One of the most promising fields of research directs its quest to the riches commonly hid beneath the surface of the mental sea. It seems probable that before the close of the twentieth century means may be discovered of sounding the depths of unconscious and sub-conscious being, means comparable with the powers of exploration which the X-ray has bestowed upon the physicist. To this alluring field of inquiry no better introduction can be given than Dr. Holmes affords us in this volume. Dr. Maudsley’s chapter on Memory treats a faculty which lies at the base of all mental wealth, the talent for accumulation, the ability to command at will every item of the mind’s crowded treasure-house. Whether remembered or forgotten, every impression stamped upon a sound, capable brain, goes to build up and refine the judgment. This power, under the name of Common Sense, is treated by Dr. Carpenter with the fulness of suggestion which always marked that veteran thinker.＂