been
the coveted prize of a dozen different conquerors (it is the gateway
of the East); why our Civil War turned on the possession of the
Mississippi River. It is the roadways we fight for, the ways in and
out, whether they be land or water. Of course, we really fought for
something better than the mere possession of a roadway, but to get
what we fought for we had to have the roadway first.

The great principle at the bottom of everything in Nature is that the
fittest survives: or, as I think it is better to say it, in any
particular conflict or struggle that thing survives which is the
fittest to survive _in this particular struggle_. This is Mr. Darwin's
discovery,--or one of them,--and the struggle for existence is a part
of the great struggle of the whole universe, and the laws of it make
up the methods of Evolution--of Development.

It is clear now, is it not, how the railway route is the direct
descendant of the tiny squirrel track between two oaks? The process of
development we call Evolution, and you can trace it all around you.
Why are your skates shaped in a certain way? Why is your gun rifled?
Why have soldiers two sets of (now) useless buttons on the skirts of
their coats? (I will give you three guesses for this, and the hint
that you must think of cavalry soldiers.) Why are eagles' wings of
just the size that they are? These and millions of like questions are
to be answered by referring to the principle of development.

Sometimes it is hard to find the clew. Sometimes the development has
gone so far, and the final product has become so complex and special,
that it takes a good deal of thinking to find out the real reasons.
But they _can_ be found, whether they relate to a fashion, to one of
the laws of our country, or to the colors on a butterfly's wing.

There is a little piece of verse intended to be comic, which, on the
contrary, is really serious and philosophical, if you understand it.
Learn it by heart, and apply it to all kinds and conditions of things,
and see if it does not help you to explain them to yourself....

"And Man grew a thumb for that he had need of it,
And developed capacities for prey.
For the fastest men caught the most animals,
And the fastest animals got away from the most men.
Whereby all the slow animals were eaten,
And all the slow men starved to death."

[Illustration]

HOW THE SOIL IS MADE

(FROM THE FORMATION OF VEGETABLE MOULD.)

BY CHARLES DA