inst a background of arrested
aboriginal development, another race evinces a radical spirit of
progress; and to these contrasted results equally the detached island
environment has contributed its share.

[Sidenote: Historical effects of island isolation; primitive
retardation.]

The historical development of island peoples bears always in greater or
less degree the stamp of isolation; but this isolation may lead to
opposite cultural results. It may mean in one case retardation, in
another accelerated development. Its geographical advantages are
distinctly relative, increasing rapidly with a rising scale of
civilization. Therefore in an island habitat the race factor may operate
with or against the geographic factor in producing a desirable
historical result. If the isolation is almost complete, the cultural
status of the inhabitants low, and therefore their need of stimulation
from without very great, the lack of it will sink them deeper in
barbarism than their kinsmen on the mainland. The negroes of Africa,
taken as a whole, occupy a higher economic and cultural rank than the
black races of Australia and Melanesia; and for this difference one
cause at least is to be found in the difference of their habitats. The
knowledge of iron, stock-raising, and many branches of agriculture were
continental achievements, which belonged to the great eastern land-mass
and spread from Egypt over Africa even to the Hottentot country; the
lack of them among the Australians must be attributed to their
insularity, which barred them from this knowledge, just as the ignorance
of iron and other metals among the native Canary Islanders[883] can only
be ascribed to a sea barrier fifty-two miles wide. The scant
acquaintance of the Balearic Islanders with iron in Roman days[884]
points to insular detachment. The lack of native domesticable animals in
the Pacific archipelagoes illustrates another limitation incident to the
restricted fauna of islands, though this particular lack also retarded
the cultural development of primitive North America.

[Sidenote: Later stimulation of development.]

On the other hand, people who have already secured the fundamental
elements of civilization find the partial seclusion of an island
environment favorable to their further progress, because it permits
their powers to unfold unhindered, protects them from the friction of
border quarrels, from the disturbance and desolation of invading armies,
to which con