IF in the rapid increase of knowledge at the present time there is a tendency for men to limit their labours more and more to one narrow field of investigation, there is also, we are glad to note, an opposite tendency leading men who have become eminent in their own particular subject to cross professional frontiers and to carry war, seldom peace, into neighbouring or even distant specialities. In the present two great publications, devoted chiefly to the human thighbone, containing more than a quarter of a million words, with tables which give the results of at least 70,000 measurements, and illustrated by 105 anatomical plates, we find Prof. Karl Pearson, the mathematician, definitely settling himself in the front bench of speculative anatomists. He cannot have expected a warm welcome in his new quarters, for there are few British anatomists who do not bear the mark of at least one of those biometrical brickbats at the throwing of which Prof. Pearson has manifested very considerable skill. They did not hurt any the less because they were nieant kindly! In spite of all their scars, however, British anatomists—nay, anatomists of every country—who study these volumes will forget their past sores and be glad to welcome him to their membership for the great service he has rendered to their subject, not only in this, but also in previous memoirs. Department of Applied Statistics, University of London, University College: Drapers' Company Research Memoirs. Biometric Series, x.: A Study of the Long Bones of the English Skeleton. By Karl Pearson Julia Bell. Text: Part i., The Femur. Chaps, i. to vi. Pp. v + 224. Atlas: Part i., The Femur. Pp. vii + plates lix + Tables of Measurements and Observations. (Cambridge: At the University Press, 1919.) Price, Text and Atlas, Part i., 30s. net. Department of Applied Statistics, University of London, University College: Drapers' Company Research Memoirs. Biometric Series, xi.: A Study of the Long Bones of the English Skeleton. By Karl Pearson Julia Bell. Text: Part i., Section ii., The Femur of Man, with special reference to other Primate Femora. Chaps, vii. to x., Appendices, Bibliography, and Indices. Pp. 225–539. Atlas: Part i., Section ii., The Femur of the Primates. Pp. vii + plates lx–ci + Tables of Femoral Measurements of the Primates; (Cambridge: At the University Press, 1919.) Price, Text and Atlas, Part i., Section ii., 40s. net.