l generality than the later examples--were
severally less unlike the fundamental form common to the group as a
whole; and thus constituted a less heterogeneous group of creatures. But
in deference to an authority for whom we have the highest respect, who
considers that the evidence at present obtained does not justify a
verdict either way, we are content to leave the question open.[2]

Whether an advance from the homogeneous to the heterogeneous is or is
not displayed in the biological history of the globe, it is clearly
enough displayed in the progress of the latest and most heterogeneous
creature--Man. It is true alike that, during the period in which the
Earth has been peopled, the human organism has grown more heterogeneous
among the civilized divisions of the species; and that the species, as a
whole, has been growing more heterogeneous in virtue of the
multiplication of races and the differentiation of these races from each
other. In proof of the first of these positions, we may cite the fact
that, in the relative development of the limbs, the civilized man
departs more widely from the general type of the placental mammalia than
do the lower human races. While often possessing well-developed body and
arms, the Australian has very small legs: thus reminding us of the
chimpanzee and the gorilla, which present no great contrasts in size
between the hind and fore limbs. But in the European, the greater length
and massiveness of the legs have become marked--the fore and hind limbs
are more heterogeneous. Again, the greater ratio which the cranial bones
bear to the facial bones illustrates the same truth. Among the
vertebrata in general, progress is marked by an increasing heterogeneity
in the vertebral column, and more especially in the segments
constituting the skull: the higher forms being distinguished by the
relatively larger size of the bones which cover the brain, and the
relatively smaller size of those which form the jaws, &c. Now this
characteristic, which is stronger in Man than in any other creature, is
stronger in the European than in the savage. Moreover, judging from the
greater extent and variety of faculty he exhibits, we may infer that the
civilized man has also a more complex or heterogeneous nervous system
than the uncivilized man: and, indeed, the fact is in part visible in
the increased ratio which his cerebrum bears to the subjacent ganglia,
as well as in the wider departure from symmetry in its c