me secretary of the Zooelogical
Society of London, in his memoir introduced the subject in the
following words:

"It is a well-known and universally acknowledged fact that we can
choose two portions of the globe of which the respective fauna
and flora shall be so different that we should not be far wrong
in supposing them to have been the result of distinct creations.
Assuming, then, that there are, or may be, more areas of creation
than one, the question naturally arises how many of them are
there, and what are their respective extents and boundaries; or,
in other words, what are the most natural primary ontological
divisions of the earth's surface?"

Mr. Sclater's answer was that there are six great regions;
Neotropical, Nearctic, Palaearctic, Ethiopian, Indian, and Australian,
and his answer, with minor alterations and the addition of a great
wealth of detail, has been accepted by zooelogy.

Two years later, however, Darwin gave a new meaning and a new
importance to Sclater's work, by the new interpretation he caused to
be placed on the words "centres of creation." Sclater's facts and
areas remained the same; Darwin rejected the idea of separate
creations in the older sense of the words, and laid stress on the
impossibility of accounting for the resemblances within a region and
for the differences between regions by climatic differences and so
forth. He raised the questions of modes of dispersal and of barriers
to dispersal, of similarities due to common descent, and of the
modifying results produced by isolation. He gave, in fact, a theory of
the "creations" which Mr. Sclater had shewn to be a probable
assumption. It was in the nature of things that Huxley should make a
contribution to a set of problems so novel and of so much importance
to zooelogy. In 1868, in the course of a memoir on the anatomy of the
gallinaceous birds and their allies, he made a useful attempt, nearly
the first of its kind, to correlate anatomical facts with geographical
distribution. Having shewn the diverging lines of anatomical structure
that existed in the group of creatures he had been considering, he
went on to shew that there was a definite relation between the
varieties of structure and the different positions on the surface of
the globe occupied at the present time by the creatures in question.
He made, in fact, the geographical position a necessary part of the
whole idea of a species