1878.] Considered from a Biological Point of View. 471 " 
is the superior stature of the male more striking than in the 
one which approaches man most nearly in its physical deve- 
lopment — the gorilla. 
But the mere difference of size is not all ; the female is 
scarcely in any normal case a mere miniature copy of the 
male. Her proportions differ ; the head and the thorax are 
relatively smaller, the pelvis broader, the bones slighter, 
and the muscles less powerful. The male in many cases 
possesses offensive weapons which in the female are wanting. 
In illustration we need only refer to the tusks of the ele- 
phant and the boar, and the horns of many species of deer. 
On the contrary, there is no instance of a female mammal 
possessing any weapon which is not also found, to at least 
an equal degree, in the male. 
Further, the superior size of the head in the male, is not 
merely due to the more massive osseous growth needful for 
the support of tusks, horns, &c., but to a proportionately 
larger development of brain. Thus, according to the recent 
investigations of M. le Bon* “ taking the mean weight of 
seventeen brains of human males, of 154 to 164 centimetres 
in height, and comparing them with the brains of seventeen 
women of the same stature, we find between the two a 
difference of 1 72 grms. (nearly 6 ounces) in favour of the 
male.” 
Summing up these faFts, commonplace but not the less 
important, we see that in the whole mammalian class, man 
included, the males are distinguished from the females, not 
merely by larger size, but by superior cerebral and thoracic 
development, and by the more general possession of offensive 
weapons. On the other hand, trite as the remark may seem, 
the organs for the nutrition of the young are exclusively 
confined to the female. Are we to suppose that these sexual 
differences are devoid of meaning, merely accidental, or 
artificial in their origin ? 
We must next inquire to what functional distinctions these 
structural differences correspond, and what is their signifi- 
cation ? It is generally admitted that among animals of 
one and the same species the larger will be found to be the 
stronger, and generally speaking physically the superior. 
Exceptions doubtless occur, but if we were to take one 
hundred men in normal health whose “ fighting weight ” 
ranged from 11 to 12 stone each, and compare them with 
another hundred averaging a stone less, we should find the 
former set able to lift greater weights, strike harder blows, 
* Comptes Rendus, lxxxvii., No. 2, p, 80. 
