4(5 
THE VOYAGE OF H.M.S. CHALLENGER. 
people or races, whose pelvic dimensions are analysed in sufficient numbers to enable one 
to obtain an average, does the female pelvis attain, in the mean of each race, dolichopellic 
proportions. Thus in the Australians and Andaman Islanders, and probably the Malays, 
whilst the males are dolichopellic the females are mesatipellic. In the Bush race the 
males are dolichopellic, the females platypellic. In the Kaffirs the males are dolichopellic, 
the females mesatipellic or platypeUic. In the Negros and New Caledonians the males 
are mesatipellic, the females are platypellic. Amongst the Europeans with a platypellic 
male index the females are also platypellic. In the South American Indians, on the other 
hand, whilst the males are platypellic the females are mesatipellic. These modifications 
all signify that in each race or people the transverse diameter of the brim, the cavity, 
and .the outlet is as a rule relatively, and indeed for the most part absolutely, wider in 
the female pelvis than in the male. 
c. Sacrum. 
A comparison of the several indices in the various tables will show that great variety 
existed in the relative length and breadth of the sacrum in the pelves measured. These 
variations may be expressed numerically by computing a sacral index by multiplying 
the breadth of the bone by 100, and dividing by the length. When the index was above 
100 the breadth of the sacrum was greater than its length, whilst, when the index was 
below 100 the sacrum was longer than broad. I propose to employ certain descriptive 
terms to express these difi'erences in the relations of the length and breadth of this bone. 
As the Greek word lepov is the equivalent of the Latin sacrum, the term dolichohieric 
would express a sacrum which was longer than broad, whilst platyhieric would express a 
sacrum in which the breadth exceeded the length. The highest index in the series was 
found in the male Esquimaux, which reached the remarkable number 139, w^iilst in one of 
the Negresses the index was as low as 89. But the difi'erences in the sacral index are 
not to be looked at only as regards their value in the pelvis in individuals, either 
male or female, but with reference to the question whether in some races of men the 
sacral index is not as a rule considerably higher than in other races. In the considera- 
tion of this question, as in that of the brim index, it is important to bear in mind that 
sex modifies the relative proportions of the parts, and that in women the sacrum as a 
rule is broader in proportion to its length than in men. 
Amongst Europeans M. Verneau has given, in sixty-three men, the mean length of 
the sacrum as 105 mm. and the mean breadth at the base as 118 mm.,, and in thirty-five 
women the mean length as 101 mm. and the mean breadth as 116 mm. If an index be 
computed from these figures the males will be found to possess a sacral index of 112*4 
and the females one of 114*8. From Gortz's measurements of the length and breadth of 
the sacrum in European women I have calculated an index of 118*9. Dr. Garson states 
