360 SCIENCE PROGRESS. 



show the development of the muscles that connected the 

 head and body — the nuchal muscles. Much importance 

 has been placed upon the form of the occipital region of the 

 Neanderthal skull by Huxley, and on that of the Bengawan 

 by Dubois. Unfortunately, only in Spy cranium No. i is 

 the part below the occipital ridge — the nuchal part — of the 

 squama occipitalis completely present ; a fragment of the 

 nuchal part is seen in the Bengawan and Spy crania No. 2 ; 

 while in the Neanderthal skull the squama occipitalis is pre- 

 sent only as far as the occipital ridge — the supra-nuchal part. 

 There are two methods by which we may approximately 

 estimate the amount of nuchal surface lost. We may infer 

 its extent from the corresponding parts of similar skulls, or 

 we may calculate it from the length of the fronto-parietal 

 arch. In the skulls of anthropoids and men the squama 

 occipitalis forms, in the large majority of individuals, about 

 one-third of the cranial vault, 1 the frontal and parietal 

 making up the other two- thirds ; thus the length of the 

 squama occipitalis is equal to half the fronto-parietal arch. 

 It is rarely less than 45 per cent, of the fronto-parietal 

 part ; so that, in the Bengawan skull, the fronto-parietal 

 arch being 220 m.m., we may calculate that the squama 

 occipitalis measured, at any rate, 100 m.m. If so, the 

 nuchal part of this skull — lying between the occipital 

 foramen and crest — measured 66 m.m., as the supra-nuchal 

 part measures only 34 m.m. Making a similar calculation 

 for the Neanderthal skull, the fronto-parietal length of 

 which is nearly 250 m.m., it is found that the lost nuchal 

 surface must have extended quite 50 m.m. below the 

 occipital crest ; the supra- nuchal part which is present 

 measures 62 m.m. In Spy cranium No. 1 the nuchal part 

 of the squama occipitalis measures 67 m.m., the supra- 

 nuchal 55 m.m.; in seven Cynocephalic Australian crania 

 the supra-nuchal varied from 50 to 55 m.m., the nuchal 



1 Cleland, "An Inquiry into the Variations of the Human Skull, 

 particularly in the Antero-posterior Direction," Phil. Trans., vol. clx., 

 1870, pp. 1 1 7-175. Also Duckworth, " A Critical Study of the Crania of 

 Aboriginal Australians in Cambridge Museum,"/. Anthrop. Instit., vol. 

 xxiii., 1892. 



