PREHISTORIC MAN. 299. 



a method which would occasionally produce a surprising 

 redistribution of affinities. Indices, it is true, are like finger- 

 marks, an admirably compact summary of individual charac- 

 teristics ; but without full morphological commentary they 

 may give very inadequate definitions of a species or variety. 



96. For these empirical measurements Dr. Sergi sub- 

 stitutes a classification into morphological types, according 

 to the general form of the skull. The method, in fact, is 

 practically that of compound photography, and the principal 

 types bear merely descriptive names such as illiptical, pen- 

 tagonal, rhomboidal, or egg-shaped ; qualified by specific 

 names, either descriptive, racial, or geographical. Deter- 

 mined by these tests, the Mediterranean Race appears, wher- 

 ever it is found, as a collocation, more or less uniformly 

 complete, of a number of such related types : and from 

 this it is inferred that the Race was already composite in 

 the farthest area of origin to which it can be traced. 



97. This centre is placed in Dr. Sergi's map, and, as 

 already indicated, in the Upper Valley of the Nile, on the 

 ground that here, among the Abyssinians, Gallas and Somalis 

 the characteristic collocation of types is most completely 

 exhibited ; the dusky complexion of a large proportion of 

 these races at the present day being discounted, partly by 

 their long-continued exposure to a more tropical climate 

 than any other branch of the race ; partly by the certainty 

 of continuous infusion of a Negroid strain from the south. 

 It is also on this hypothesis possible to explain the very 

 close likeness between the Eastern Hamitic and the Semetic 

 types, and the ambiguous position and composite character 

 of the Egyptian nationality between them ; for a migration 

 seawards down the Nile must necessarily divide at the 

 Delta into two streams ; and of these one must then move 

 westwards along the Libyan coast, and the line of the oases, 

 formerly much larger, which lie behind it, while the other 

 must move eastwards into North Arabia and South Pales- 

 tine ; where Prof. Flinders Petrie has shown that the 

 primitive Amorite population exhibited a physical type, and 

 a fairly advanced civilisation almost indistinguishable from 

 that of the Libyan element in pre-Dynastic Egypt. 



