THE EVOLUTION OF THE EYEBROW REGION OF THE FOREHEAD. 309 



trochlear and supraorbital grooves, notches, and occasional foramina. Anyone who 

 makes a comparative study of the region will be naturally led to inquire, in the case of 

 Type II., whether the sulcus which separates the superciliary and the supraorbital elements 

 is not in great part produced by the supraorbital nerve in the first part of its course 

 on the forehead. When I began my investigation this view appealed strongly to me, and 

 gained force from a dissection which I made of a young yellow baboon, in which the 

 nerve undoubtedly occupied the whole length of the sulcus in question. Subsequent 

 research, however, has shown that, while the nerve may turn outwards in the groove for 

 a short distance, the sulcus cannot in any sense be regarded as a nerve pathway. 



Having now taken a general survey of the morphological characters of the eyebrow 

 eminences in man and the apes, we are in a position to discuss the view expressed by 

 Professor Schwalbe that these features alone are sufficient to constitute a specific 

 difference between the Neanderthal race and all other races of mankind. In coming to 

 this conclusion, it seems to us that Schwalbe in some degree exaggerates the importance 

 of the features in question, and has failed to take into account the numerous individual 

 crania of recent races which are found to some extent filling up the gap which exists 

 in this respect between the Neanderthal cranium and the crania typical of the races of 

 the present day. 



The leading peculiarities of the Neanderthal eyebrow region are : — 



1. Its striking degree of prominence. 



2. Its external configuration and its morphological constitution. 



3. Its relation to the cerebral part of the frontal bone and to the roof of the orbit. 

 In so far as 1 and 2 are concerned, the Neanderthal cranium may be said to fall within 

 the limits of the races which exist at the present day. As we have seen, individual 

 crania are found amongst the Australians which exhibit very nearly, if not quite, as 

 great a prominence in the glabellar region. Nor are the general configuration and the 

 constitution of the eyebrow projection which are characteristic of the Neanderthal group 

 peculiarities which belong to this race alone. In these respects they are associated in 

 Type III. with many individuals of other existing races. 



As Schwalbe has recognised, it is in the relation of the supraorbital projection to the 

 cerebral and the orbital cavities that the most important distinction lies. But even 

 in this respect we find in recent man transition forms, and we have indicated the New 

 South Wales cranium as a case in point. Further, it has long been known that in the 

 Australian, notwithstanding the projection of the eyebrow region, the tendency is 

 towards the formation of frontal air-sinuses of small size. In the Australian skull, as in 

 the Neanderthal cranium, the eyebrow eminence is as a rule largely formed by a massing 

 of the bone in front of the air-chamber. 



It is doubtful if much proKt can be derived from a discussion as to whether the 



