Dr. A. G. Roshdestwenski, of Moscow, has made many careful measurements of the head in 1,600 Russians. He finds that the relative as well as the absolute size of the head depends upon the growth of the body. This is true of both sexes. The absolute size of the head is greater in big people; the relative size is less. Men attain the maximum size of the cranium earlier than women, men reaching the full size at 20 years, women five years later. This seems a novel result.