448 PRINCIPAL SIR WM. TURNER ON 



it more distinct, but in neither was the frontal mesial ridge seen ; the Stephanie 

 diameter was in one approximately 97, in the other 106 mm. In Pithecanthropus 

 the frontal sloped backwards with a continuous curve from the glabella and supra- 

 orbital region to the coronal suture ; the frontal eminences were not visible, and the 

 bone had a median ridge ; the Stephanie diameter was approximately 82 mm. # 



The bregma in the Tasmanians was flattened and the raised area formed a bregmatic 

 eminence continued backwards from the frontal, whilst it was bounded on a lower 

 plane on each side by the longitudinal depression. 



In the Australians the sagittal ridge usually commenced at the bregma and passed 

 backwards along the line of the suture ; the vault sloped steeply downwards from the 

 ridge to the temporal lines and parietal eminences, and the transverse curvature of the 

 parietals was roof-shaped. In the Scottish skulls the sagittal ridge was absent or very 

 faint ; at and in proximity to the bregma the transverse curvature in the parietal region 

 was rounded, so as to give requisite accommodation for the frontal and parietal lobes of 

 the cerebrum. In the Neanderthal was a faint bregmatic eminence, but no sagittal 

 ridge ; the transverse curvature in the parietal region was rounded from side to side, 

 and the greatest width was approximately 152 mm. The Spy crania had no definite 

 bregmatic eminence ; the sagittal ridge was indicated in one but not in the other ; the 

 vault from the sagittal suture to the parietal eminences and temporal ridges formed a 

 gentle curve; the parietal width in one was 147 and in the other 154 mm. In 

 Pithecanthropus the bregmatic eminence was distinct ; the vault was flattened and 

 there was no sagittal ridge ; the temporal curved lines were strong ; the greatest width 

 was 130 mm. 



Much attention has been paid of late years to the inclination of the frontal bone 

 and its consequent effect on the frontal vault of the cranium, as well as to a possible 

 change in the position of the bregma. Schwalbe has diligently studied this question, 

 and has come to the conclusion that the inclination of the frontal hinges upon two 

 factors, the degree of elevation or depression of the bone, and the degree of its curva- 

 ture.t Schwalbe believed that the bregma could be displaced forwards, so that the 

 frontal became more or less vertical. To measure the extent of this displacement he 

 drew (a) a base line from the most prominent part of the glabella to the inion ; (b) 

 a line from the glabellar end of the base line to the most projecting part of the frontal, 

 and he named the angle at their junction the frontal angle ; (c) a line from the bregma 

 to the glabellar end of the base line, and he named the angle at the junction of these 

 lines the bregma angle. The more open the angles the more was the frontal region 

 elevated. Klaatsch also attached great importance to the determination of the bregma 

 angle. In Pithecanthropus, he said, it was very low, 41°, in the Neanderthal skull 45° ; 



* These descriptions of the palaeolithic skulls and Pithecanthropus are written from casts of the skulls in the 

 University Museum. Owing to some of the surface markings heing obscure, the measurements between these points 

 are stated approximately. 



t "Studien iiber Pithecanthropus erectus" Zeitsch. filr Morph. und Anat., Band 1, Heft 1, S. 1, 1899; "Der 

 Neanderthal Sehudel," Bonner Jahrbucher, Heft 106, 1901. 



