Warman, P. C., 67 Warming, E., 89, 136 Washburn, M. F., 106, 107 Wasmann, E., 18, 120, 130 Watson, J. B., 107, 120 Watson, J. R., 148 Waxweiler, E., 132 Webster, F. M., 130 Weed, C. M., 130 Weiss, F. E., 90 Wendell, B., 66 Wesenberg-Lund, C., 134, 136, 140 Wheeler, W. M., 18, 19, 22, 107, 111, 120, 126, 130, 131, 149 Whipple, G. C., 78 White, C. A., 22 Whitman, C. O., 103, 121 Wickham, H. F., 121, 149 Wilson, E. B., 98 Wilson, H. M., 65 Winterstein, H., 95 Wood, G. M., 68 Wood, J. G., 140 Wood, T., 140 Woodman, J. E., 146 Woodworth, J. B., 86 Woolley, E. C., 69 Wright, A. H., 64 Yearsley, M., 111 Yerkes, A. W., 106 Yerkes, R. M., 105, 106, 107, 121 Yoakum, C. S., 121 Zacharias, O., 130 Zoethout, W. D., 99 Zon, Raphael, 89 The following pages contain advertisements of a few of the Macmillan books on kindred subjects. =Genetics.= An Introduction to the Study of Heredity BY HERBERT EUGENE WALTER Assistant Professor of Biology, Brown University _Cloth, 12mo, $1.50 net; postpaid, $1.63_ In his “Genetics” Professor Walter summarizes the more recent phases of the study of heredity and gives to the non-technical readers a clear introduction to questions that are at present agitating the biological world. Professor Walter’s conception of sexual reproduction is that it is a device for doubling the possible variations in the offspring, by the mingling of two strains of germ plasm. The weight of probability, he concludes, is decidedly against the time-honored belief in the inheritance of acquired characters. Professor Walter also predicts that the key to this whole problem will be furnished by the chemist, and that the final analysis of the matter of the “heritage carriers” will be seen to be chemical rather than morphological in nature. In the practical application of this theory to human conservation or eugenics, it would follow that the only control that a man has over the inheritance of his children is in selecting his wife. Professor Walter holds, if only modifications of the germ plasm can count in inheritance, and if these modifications come wholly from the combination of two germ plasms, then the only method of hereditary influence is in this selection. “I find that it is a very useful study for an introduction to the subject. Professor Walter has certainly made one of the clearest statements of the matters involved that I have seen, and has made a book which students will find very useful because he keeps everything in such entirely simple and clear outlines, and at the same time he has brought the book up to date.”--PROFESSOR LOOMIS of Amherst College.