ot be surprised to find
it supported by an array of facts depending on the principle that the
appearance of new forms does not observe a certain inevitable order, or
stand in a certain relation to time. From individual development it
might seem as if the advancing procession of an organism is such that
specific forms ever appear in a certain order one after another, and at
certain intervals; but the fallacy of such a conclusion is apparent when
we attend to the orderly procedure of the physical conditions to which
the developing organism is exposed. [Sidenote: Development is in place,
not in time.] The passing through a given form at a given epoch is due
to the relation being to space and its conditions, not to time. And so
in the life of the earth, if development were according to time, we
should have an orderly succession of grades as the earth grew older, and
in all localities, at a given moment, the contemporary organisms would
be similar; but if it were according to space, that rigorous procedure
would not occur; in its stead we should have a broken series, the
affiliation being dependent on the secularly continuous variation of the
physical condition.

Now this was discovered to be the case. For instance, throughout the
northern hemisphere, during the Tertiary period, an extinct placental
Fauna was contemporaneous with an extinct marsupial Fauna in Australia.
If the development was proceeding according to time, by an innate nisus,
and not according to external influences, the types for the same epoch
in the two hemispheres should be the same; if under external influences,
irrespective of time, they should be, as they were found to be,
different.

If true-going clocks, which owe their motion to their own internal
mechanism, were started in all countries of the earth at the same
instant, they would strike their successive hours simultaneously. But
sun-dials, which owe their indications to an exterior cause, would in
different longitudes tell different times, or, when the needful light
was absent, their shadows would altogether fail.

As to the vegetable kingdom, the principles that hold for the animal
again apply. At a very early period, even before the deposit of the
coal, all the distinct forms of vegetable tissue were in existence, and
nothing to prevent, so far as time was concerned, their being united
together all over the world into similar structural combinations. And,
in truth, as the botany of the Coal p