THE VARIOUS FORMS OF THE SKULL. 83 



The capacity of the cranium affords the most convenient indication of the development 

 of the brain. 1 It is ascertained by filling the cranial cavity with shot, and then measuring 

 the contained quantity in a properly graduated vessel, special precautions being taken to 

 ensure as nearly as possible an equal pressure in both operations. The capacity of the normal 

 human cranium varies from 1,000 to 1.800 cubic centimetres (about 60 to 110 cubic inches), 

 with an average in all races of 1.400 cubic centimetres (85 cubic inches). Skulls with a 

 capacity of from 1,350 to 1,450 cubic centimetres are placed in a middle group and termed 

 mewcephalic, those exceeding 1.450 cubic centimetres in capacity are mefjacejrftalic, and those 

 below 1.350 cubic centimetres are microcepTialio (Flower). The following examples are of 

 males only : 



Eskimo . . . 



European 



Chinese and Mongols. 



African Negroes 



Native Australians . 



Andaman Islanders . 



Cub. centira. 

 1500 

 1480 

 1430 

 1350 

 1300 

 1280 



Cub. inches. 

 91-5 

 90-3 

 87-3 

 82-4 

 79-3 

 78-1 



Before proceeding to the consideration of the linear measurements it is necessary to refer 

 to certain definite points on the surface of the skull from which such measurements are 



Fig. 84. SIDE VIEW OF SKULL 



OP A MALE AUSTRALIAN. 



(After Flower.) 



A, alveolar point ; S, sub- 

 nasal point ; N, nasion ; Gl, 

 glabella ; Op, ophryon ; Bg, 

 bregrua ; Ob, obelion ; L, 

 lambda ; 0, occipital point ; 

 I, inion ; B, basion ; Pt, 

 pterion ; St ; stephanion ; As, 

 asterion ; Gl O, length of 

 cranium ; B N, basinasal 

 length ; B A, basiaJveolar 

 length ; N S, nasal height. 



taken, or which have a 

 particular importance as 

 presenting varieties of more 

 or less frequent occurrence, 

 and to which special names 

 have been given not of ordi- 

 nary use in descriptive 

 anatomy. These are : 



Alveolar point (fig. 84, A). The centre cf the anterior margin of the upper 

 alveolar arch. 



Subnasal or spinal point (S). The middle of the inferior border of the anterior nasal 

 aperture at the base of the nasal spine. 



Nasion or nasal point (N). The middle of the naso-f rental suture. 



Ophryon or snpraorl)ital point (Op). The middle of the supraorbital line, which, drawn 

 across the narrowest part of the forehead, separates the face from the cranium. 



Bregma (Bg). The point of junction of the coronal and sagittal sutures. 



Obelion (Ob). The region situated between the two parietal foramina where the sagittal 

 suture is more simple than elsewhere, and where its closure generally commences. 



Lambda (L) The point of junction of the sagittal and lambdoid sutures. 



Occipital point (0). The point of the occiput in the median plane most removed from the 

 glabolla. 



1 According to Manouvrier (Mem. de la Soc. d'Anthrop. de Paris, 2 ser., t. iii, 1885), the weight 

 of the brain in grammes may be approximately ascertained by multiplying the cranial capacity in cubic 

 centimetres by '87. But it is to be remarked that Manouvrier's capacities were obtained by Brora's 

 method, which undoubtedly gives too high results. Welcker proposes (Arch. f. Anthrop., xvi, 51) a 

 sliding scale, ranging from 91 gr. of brain-weight to 100 ccm. of cranial capacity for skulls with a 

 capacity of 1200 ccm, to 95 gr. to 100 ccm. for skulls of 1600 ccm. capacity. Thus 1480 x '938 = 

 1S88 gr., which agrees closely with the average European brain- weight as ascertained by direct 

 observation. 



a 2 



