The intent of this paper is to consider the nature of the Old World population represented by the fossil remains of palaeoanthropic man, of Homo neanderthalensis. The propriety of the particular name used to define the systematic position of these human beings can be usefully considered at a later point in this paper. My reasons for dwelling primarily on the Neanderthal group is that it provides the largest sample of fossil man now extant, has a considerable time range and a wider geographic distribution than do the fossil men of Peking or of Java, and in all these respects is also somewhat superior to the fossil men of the terminal Pleistocene. Lastly, I know quite intimately a part of this fossil Neanderthal material.