r Science Monthly, Feb., 1876.)]

Let us now apply this theory of evolution to the physical world. No
determined opposition by the mass of people is likely to be manifested
to the doctrine of evolution as applied to the physical world, or even
to the vegetable or animal world up to man; but the minute man is
included--then is a voice raised up against it, and it was for this
reason that Darwin in his first work on the "Theory of Descent" did not
mention man as being included in the evolutionary series. He knew too
well the foolish human weakness that existed.

In a recent work by Prof. Challes, he states that he regards the
material universe as "a vast and wonderful mechanism of which the least
wonderful thing is its being so constructed that we can understand it."

The following is a brief description of the various theories of the
world's formation:

_First Theory._--By the first theory the world is supposed to have
existed from eternity under its actual form. Aristotle embraced this
doctrine, and conceived the universe to be the eternal effect of an
eternal cause; maintaining that not only the heavens and the earth, but
all animate and inanimate beings, are without beginning. To use Huxley's
illustration: If you can imagine a spectator on the earth, however far
back in time, he would have seen a world "essentially similar, though
not perhaps in all its details, to that which now exists. The animals
which existed would be the ancestors of those which now exist, and like
them; the plants in like manner would be such as we have now, and like
them; and the supposition is that, at however distant a period of time
you place your observer, he would still find mountains, lands, and
waters, with animal and vegetable products flourishing upon them and
sporting in them just as he finds now." This theory being perfectly
inconsistent with facts, had to be abandoned.

_Second Theory._--The second theory considers the universe eternal, but
not its form. This was the system of Epicurus and most of the ancient
philosophers and poets, who imagined the world either to be produced by
fortuitous concourse of atoms existing from all eternity, or to have
sprung out of the chaotic form which preceded its present state.

_Third Theory._--By this theory the matter and form of the earth is
ascribed to the direct agency of a spiritual cause. It is needless to
say that this last theory has for its basis the popular account,
generally cre