section,
which deals with the proofs that all civilised nations were once
barbarians, Darwin again uses the results gained by other
investigators, such as Lubbock and Tylor. There are two sets of facts
which prove the proposition in question. In the first place, we find
traces of a former lower state in the customs and beliefs of all
civilised nations, and in the second place, there are proofs to show
that savage races are independently able to raise themselves a few
steps in the scale of civilisation, and that they have thus raised
themselves.

In the sixth chapter of the work, Morphology comes into the foreground
once more. Darwin first goes back, however, to the argument based on
the great difference between the mental powers of the highest animals
and those of man. That this is only quantitative, not qualitative, he
has already shown. Very instructive in this connection is the
reference to the enormous difference in mental powers in another
class. No one would draw from the fact that the cochineal insect
(Coccus) and the ant exhibit enormous differences in their mental
powers, the conclusion that the ant should therefore be regarded as
something quite distinct, and withdrawn from the class of insects
altogether.

Darwin next attempts to establish the _specific_ genealogical tree of
man, and carefully weighs the differences and resemblances between the
different families of the Primates. The erect position of man is an
adaptive character, just as are the various characters referable to
aquatic life in the seals, which, notwithstanding these, are ranked as
a mere family of the carnivores. The following utterance is very
characteristic of Darwin:[102] "If man had not been his own
classifier, he would never have thought of founding a separate order
for his own reception." In numerous characters not mentioned in
systematic works, in the features of the face, in the form of the
nose, in the structure of the external ear, man resembles the apes.
The arrangement of the hair in man has also much in common with the
apes; as also the occurrence of hair on the forehead of the human
embryo, the beard, the convergence of the hair of the upper and under
arm towards the elbow, which occurs not only in the anthropoid apes,
but also in some American monkeys. Darwin here adopts Wallace's
explanation of the origin of the ascending direction of the hair in
the forearm of the orang,--that it has arisen through the habit of
holding th