was once represented by a nebula of some sort, and we
may speak of the evolution of the sun and the planets. But since it has
been _the same material throughout_ that has changed in its distribution
and forms, it might be clearer to use some word like genesis. Similarly,
our human institutions were once very different from what they are now,
and we may speak of the evolution of government or of cities. But Man
works with a purpose, with ideas and ideals in some measure controlling
his actions and guiding his achievements, so that it is probably clearer
to keep the good old word history for all processes of social becoming
in which man has been a conscious agent. Now between the genesis of the
solar system and the history of civilisation there comes the vast
process of organic evolution. The word development should be kept for
the becoming of the individual, the chick out of the egg, for instance.

Organic evolution is a continuous natural process of racial change, by
successive steps in a definite direction, whereby distinctively new
individualities arise, take root, and flourish, sometimes alongside of,
and sometimes, sooner or later, in place of, the originative stock. Our
domesticated breeds of pigeons and poultry are the results of
evolutionary change whose origins are still with us in the Rock Dove and
the Jungle Fowl; but in most cases in Wild Nature the ancestral stocks
of present-day forms are long since extinct, and in many cases they are
unknown. Evolution is a long process of coming and going, appearing and
disappearing, a long-drawn-out sublime process like a great piece of
music.

[Illustration: _Photo: Rischgitz Collection._

CHARLES DARWIN

Greatest of naturalists, who made the idea of evolution current
intellectual coin, and in his _Origin of Species_ (1859) made the whole
world new.]

[Illustration: _Photo: Rischgitz Collection._

LORD KELVIN

One of the greatest physicists of the nineteenth century. He estimated
the age of the earth at 20,000,000 years. He had not at his disposal,
however, the knowledge of recent discoveries, which have resulted in
this estimate being very greatly increased.]

[Illustration: _Photo: Lick Observatory._

A GIANT SPIRAL NEBULA

Laplace's famous theory was that the planets and the earth were formed
from great whirling nebulae.]

[Illustration: _Photo: Natural History Museum._

METEORITE WHICH FELL NEAR SCARBOROUGH, AND IS NOW TO BE SEEN IN THE
NATURAL HIST