The objective point and the rate of motion thus stated, exact science holds her peace. Here genuine knowledge stops; and we can proceed further only by the aid of that imagination which men of science need to curb at every moment. But let no one think that the sun will ever reach the so-called apex. To do so would mean cosmic motion upon a straight line, while every consideration of celestial mechanics points to motion upon a curve. When shall we turn sufficiently upon that curve to detect its bending? ’Tis a problem we must leave as a rich heritage to later generations that are to follow us. The visionary theorist’s notion of a great central sun, controlling our own sun’s way in space, must be dismissed as far too daring. But for such a central sun we may substitute a central center of gravity belonging to a great system of which our sun is but an insignificant member. Then we reach a conception that has lost nothing in the grandeur of its simplicity, and is yet in accord with the probabilities of sober mechanical science. We cease to be a lonely world, and stretch out the bonds of a common relationship to yonder stars within the firmament. A BIOGRAPHICAL SKETCH OF AN INFANT[H]. BY CHARLES DARWIN. [H] Reprinted from _Mind_, July, 1877. [Child-study has recently become a most active department of psychology. It is the serious pursuit of men of science and the fad of women’s clubs; a late accession to the magazines devoted to it comes from Japan. In spite of this wide-spread zeal, few of the followers of child-study have ever heard of one of the most valuable contributions to it. And in spite of the eminence of the author, Darwin’s observations on the mental growth of his child are practically unknown to most zoölogists and psychologists. It is a witness to the breadth of Darwin’s interests that he should have been among the few men who anticipated by a generation or more what is now so wide a movement in psychology. His retention of his notes for thirty-seven years before publishing them is thoroughly characteristic. In this respect there is a notable difference between Darwin and the present-day enthusiasts for child-study.]