THE ABORIGINES OF TASMANIA. 451 



point at the base, should be selected, aud the diameter from it to the bregma should be 

 regarded as the vertical diameter. Since then the basi-bregmatic diameter has been 

 generally accepted, and was adopted in my Challenger Reports and subsequent memoirs. 

 Experience has shown that in a large number of skulls this diameter may be regarded 

 as giving the maximum height, though in some specimens this may lie a few milli- 

 metres behind the bregma. 



In the description of the Tasmanian skulls in Part. I. and of the Brussels skull in 

 the present part, I have shown that the height was less than the breadth and the 

 vertical index was therefore less than the cephalic ; the mean vertical index in the 

 Tasmanians was 71*1 and the mean cephalic index 7472, whilst the mean breadth- 

 height index of the series was 95 '5. In my Challenger Report, 1884, I analysed the 

 relations of the height and breadth in one hundred and fifty crania of Australian 

 aborigines, in eighty-five of which the height was more than the breadth ; in fifteen 

 they were equal ; in fifty-one the height was less than the breadth, a character which 

 was found especially in skulls from South Australia. In a series of one hundred and 

 fifty Scottish skulls of both sexes I found that with six exceptions the breadth exceeded 

 the height, and the cephalic index was more than the vertical. 



As regards the cubic contents the Tasmanians have a small cranial cavity. In my 

 first series the capacity of the males ranged from 1100 to 1430 in one quite exceptional 

 skull, with a mean 1235 c.c, and in the Brussels skull the capacity was only 1080 c.c. 

 When conjoined with the measurements of other observers the mean capacity of the 

 skull in Tasmanian men worked out between 1200 and 1300 c.c, although a fair pro- 

 portion were only about 1100. My measurements of the Australians gave 1293 as the 

 mean capacity of twenty men, and the range in them was from 1044 to an exceptional 

 1514 c.c. In comparing crania which approximated to each other in maximum length 

 the capacity of the cranial box would be influenced by the relative proportions of their 

 dimensions in breadth and height, and in the compensating influence which an increase 

 in one of these two diameters would exercise over a diminished diameter in the other. 

 Thus skulls with a vault more strongly arched in a sagittal direction, but roof-shaped 

 in the transverse arc, do not necessarily have more brain space than crania with a more 

 flattened form of the vault, if the latter have a greater breadth. The Australians and 

 Tasmanians, notwithstanding the differences in the relative dimensions either of breadth 

 or height, approached each other in the mean cranial capacity. In the Scottish skulls, 

 again, where length, breadth and height are all well marked, I obtained in seventy-three 

 males a range from 1230 to 1 855 c.c, the mean being 1478 c.c, and the lowest skull 

 measured was only 5 c.c. less than the mean capacity of the Tasmanians. 



It is difficult to state precisely the cranial capacity of Pithecanthropus, the Neander- 

 thal and Spy crania. Schwalbe has given 1015 c.c. as the measured capacity of the 

 skull cap, and 1230 as the estimated capacity of the Neanderthal cranium. Pithe- 

 canthropus was estimated by Dubois, its discoverer, as having a capacity of possibly 

 1000 c.c It approached or was equal to the capacities of individual skulls which I 



TRANS. ROY. SOC. EDIN., VOL. XLVII. PART III. (NO. 16). 67 



