242 



Annals of the South African Museum. 



mann. The latter contrast is somewhat unsatisfactory owing to 

 the usual reason — the small number of skulls available for examina- 

 tion. The latter shows that the Hottentots, still more therefore the 

 Bushmen, are distinctly separated in all dimensions from the Kaffirs, 

 and in most dimensions from the peoples of Nyasaland, but although 

 they probably differ equally from the Herrero tribes of German 

 territory, the differences are not demonstrably unaffected by chance. 



Groups Contuastkd. 



A figure above 2*0 indicates considerable odds against the 

 explanation of the differences between the respective average 

 being random sampling, while a figure above 3-0 indicates the 

 practical exclusion of chance. 



The apparent relationships between the dimensions of the crania 

 from the several groups having been determined, it seemed advisable 

 to endeavour to determine if any of these groups were more mixed 

 than the others. The groups showing the widest range of variation 

 in dimensions might be expected to be more probably a mixture of 

 individuals of different stocks. For this purpose the coefficient of 

 variation of each group was calculated. 



The coefficient of variation is one hundred times the quotient 



of the standard deviation divided by the actual value of the 



Standard deviation x 100 ^^ «i • ^ mi i.i i. j i 



average : ^ = Coeflacient, Thus the standard 



° Average 



deviation of head length in the Strandloopers is 5"6276, the average 



