24 
THE VOYAGE OF H.M.S. CHALLENGER. 
the corresponding indices in the female. In the male the ilium was much longer than in 
the female, but the breadth of this bone was almost equal in the two specimens, so that 
there was a great difference in their respective iliac indices. The difference between 
the lengths of the ilium and ischium was much greater in the man than in the woman. 
The innominate index was distinctly greater in the male than in the female. In both, 
the breadth of the sacrum exceeded the length, the index in the male being 106, in the 
female 112. 
General Eemarks on the Pelves. 
The pelves, the measurements of which are recorded in the foregoing tables, are 
from a number of races living for the most part a savage and primitive life, and in 
several instances, as the Andaman Islanders, Bush, and Laplanders, are people of 
diminutive stature. They consist, including both pelves and separate innominate bones, 
of twenty-four adult males and fourteen adult females. 
1. Sexual Characters. 
As sex influences in a very important manner the form and proportions of the 
pelvis, I shall, in the first place, make some observations on their sexual characters. 
The female pelvis in its construction and proportions is modified so as to give space 
for the enlargement of the uterus during gestation, and for the expulsion of the child 
during parturition ; and, in relation to these two functions, its inlet and outlet require 
to be more open, and its cavity more capacious and shallower than in the male. In 
accordance with the shorter stature and generally smaller bulk of a woman than of a 
man, the external dimensions of the entire pelvis are on a smaller scale in the female 
than in the male. The mean height in the series of adult males now before me was 197, 
and in the adult females 175 ; the mean breadth in the males was 248, and in the 
females 235. It will be seen therefore that the height diminished in a greater ratio 
than the breadth, and this difi'erence is expressed by the mean breadth-height index, 
which was only 74 for the adult females, but 80 for the adult males. The pelvic cavity 
was as a rule shallower in the women than in the men ; the mean depth in the females 
was 85 mm., in the males 95 mm. 
The proportions of the obturator foramen also difi'ered in the two sexes, for whilst 
there was not, as a rule, any very marked difi'erence in its transverse diameter in the 
two sexes, the vertical diameter, in accordance with the greater depth of the pelvic 
cavity, was considerably more in the males than in the females. The females therefore 
had a much higher obturator index than the males ; the mean of the series for the 
females was 73, for the males 67. The greater relative capacity of the female than of 
the male pelvis, and the relatively larger areas of the inlet and outlet, are also shown in 
