186 SECTIONAL ADDRESSES. 



If modern men are descendants of one ancestral group, it was probably 

 a group of Pleistocene and possibly of mid-Pleistocene date. At that 

 period, we may take it that the requisite climatic conditions obtained in 

 various parts of the belt now forming the Sahara and S.W. Asia, for the 

 belts of climate then lay farther south, and the winter westerlies apparently 

 visited that belt ; it is interesting that the Sahara shows a good deal 

 of evidence of inhabitants of possibly mid-Pleistocene date. We may, 

 perhaps, venture to ' place ' the ancestors of modern man in the zone 

 from the Atlantic edge of the Sahara to Persia, and may think of several 

 groups not all exactly alike. Those on the colder side of the zone may 

 well have been distinguished by greater mental activity. 



What were the early modern men like ? Firstly, as all men of modern 

 type walk nearly erect and as the older extinct types of man did not, we 

 may argue that an advance, still incomplete in some cases [Grimaldi 

 (lower levels) and Chancelade], towards the erect posture was character- 

 istic of early modern man. Next, nearly all healthy men show some 

 tendency to produce brown pigment, and, save in N.W. Europe, have 

 dark hair and eyes. In fact, these are almost universal in the rest of the 

 world except for migrants from North Europe, in which area (possibly 

 also, slightly, in parts of N.E. Asia) therefore a process of depigmentation 

 has most probably occurred. So it is likely that early modern men were 

 more or less brown-skinned, dark-haired and dark-eyed, and if this be 

 so they doubtless lived where there was a good deal of summer sunshine, 

 as, no doubt, there was in the region indicated. 



Next we note that, however strong the jaws and brow-ridges of modern 

 types of men (fossil or living) may be, they are less strong and project 

 far less thaii those of the most ancient types of men. Reduction of jaws 

 and brow-ridges is thus a process we can postulate, and we may go one 

 step farther and associate this with progress towards the erect posture. 

 Reduction of face and jaws would certainly make it easier to balance 

 the head on the end of the vertebral column, and this reduction was. 

 undoubtedly made possible by increased use of the hands. There was. 

 also, no doubt, some influence of what Roux called the ' Struggle of the 

 Parts,' according to which parts that are of increasing importance draw 

 nutrition during development from their neighbours. In this case it 

 would be the growing fore-brain that was capturing energy. It may also 

 be that there has been a relative reduction of the pituitary secretions 

 or of one or other of them, and it has already been suggested that there 

 had been a liberation of thyroid secretion from old duties, or even an 

 increase of that secretion. 



III. — Early Forms of Modern Man — A Brief Summary. 



Among the early (Aurignacian and Solutrean) examples of modern 

 men we notice a good deal of difference of characters, and this suggests 

 a number of ancestors spread over a fairly large zone rather than an origin 

 from a very small group of very localised origin. It is admitted that the 

 number of skeletons known is, as yet, too small for us to argue with con- 

 fidence about races and migrations in that early time. Nevertheless, it 

 is useful to have some working hypothesis, and for this purpose we shall 



