422 TWO REMARKABLE SKULLS 



The Foramino-basal Angle. — This angular cranial measure- 

 ment is usually associated with the name of Sir William 

 Turner'^'*''^ who made extensive use of it in measuring the 

 Challenger collection of skulls. It was found to be 146.5° 

 in No. 1 skull and 148° in No. 2. This closely approximates 

 to the figure of 147° which was estimated by Huxley^^''^ in 

 a Melanesian skull. Duckworth^^''^ gives 149° 30' as the aver- 

 age size of this angle in two European skulls. It is evident 

 therefore that the size of the foramino-basal angle varies 

 very slightly throughout all types of modern hominidae. 

 Indeed its range of variation is so small that it cannot by 

 itself be utilised as a determining factor in a comparative 

 study of the human race. It is very serviceable however 

 in comparing the skull of man with that of lower animals, 

 where it appears to become consistently smaller the further 

 down the Mammahan series one goes. This profound altera- 

 tion is due to the fact that the foramen magnum which in 

 man lies practically in a horizontal plane, comes to look 

 more and more backwards as one descends the animal scale. 

 For example Duckworth ^*^^ records a foramino-basal angle 

 of 120° in the gorilla and one of 108° in the dog. 



Some Additional Features of the Two Skulls. — No. 1 skull 

 was remarkably thin, the upper part of the frontal bone 

 being only 4.5 mm. in thickness. No. 2 skull, on the other 

 hand possessed a thickness twice as great on the average 

 as that of No. 1. The lower parts of the tempoial fossae 

 in both skulls were remarkably capacious, the distance be- 

 between the inner surface of the xygoma and the bottom of 

 the fossa being as much as 25.5 mm. in No. 2 skull and 

 24 mm. in No. 1. These large gaps indicated of course 

 that the temporal muscles had been very powerfully developed, 

 as one would have expected in a race addicted to cannibalism 

 and unconventional mastication. The various air sinuses 

 were remarkably large. Those in the frontal bone were 

 very spacious, their influence in producing the excessively 



