Behind the gem, or flower, or shell lies the force that produced it, and the flash of the diamond, the tint of the rose, and the pearly chambers that once held a living form all tell the story of the power, circumstance, and condition to which they owe their existence.

Thus, whether the naturalist studies the history of the sun, the earth, a leaf, or a drop of dew, he studies the forces which produced them; and it has been the aim of science to these forces and to define their laws as clearly as possible.

Every branch of natural history records some facts that have been found out by certain special workers, and geology, botany, zoology, and physics are merely terms which express the sum of knowledge that has been gained concerning the history of the earth as related by the rocks, the laws of vegetation, of animal life, and of the hidden forces of nature as shown in electricity, chemistry, heat and other agents.

And of all these studies none have been found more interesting to naturalists than those of the forces which relate to and govern life, whether it be life as expressed in the animal or vegetable kingdoms.

The student has found that after he has counted the stamens and pistils of a flower and assigned it its place in the world, there still remains the mystery of its existence, the power that passed away from it with its separation from the stem, and allied it to the earth and stones and other dead matter around it.

And the same is true of the animal kingdom. The bird that falls by the sportsman’s gun, ere the echo of its song has died away is changed in a moment of time from a creature with will, and power, and voice, to an object as senseless as the withered flower. If the dead bird were examined all its organs would be found in their places, but the mysterious force called life would have departed—flown away as invisibly as the perfume steals from the flower.

The science which treats of the life-force—its laws, limitations, and capabilities—is called biology, and is one of the latest developed of all the sciences, though even in the early ages of the world some attempt was made to grasp the meaning of life and its strange negation, death.

But, for the most part, these attempts ended in definitions which left no new light on the subject. "Life is the breath of God," said the old sages, and any effort to find out the principles governing its development would have been deemed unphilosophical in an age where all experiment was ridiculed and all questions of natural science were answered by the reason alone.

The old belief in the possibility of finding the elixir of life which would confer immortality resulted, as has been seen, in a knowledge of laws of chemistry which might have been unrevealed for ages, but for this impelling motive.

And strange as it may appear, the old alchemists, who seemed to grope blindly in the dark, were after all on the true path, for it is to chemistry that we owe much of our knowledge of the laws that govern life, and the ignis fatuus  of the Middle Ages has thus become the torch that has led modern science into the ways of the truth.

In the eighteenth century Lamarck advanced some views in regard to the different forms of animal life which may be accepted as the definite beginning of modern biology.

Lamarck suggested that the varying species of animals were perhaps due to such influences as climate, soil, food, and other things, and that the appearance and instincts of animals might change just as much under special conditions as a plant may be changed at the will of a florist.

These changes would, of course, only occur at great intervals of time, as nature works slowly; and the study of fossils and their connection with living species would thus not only be useful to the biologist, but to the geologist, in determining the ages of the different strata of the earth.

Historical research, reaching back to the remotest times, can arrive at no period when wheat, the highest developed of all the cereals, was not found in its present form. And, as it is well-known that this grain must have been found originally in a wild state, whence it was rescued by the tribes that were exchanging barbarism for civilization, some idea of the length of time necessary to effect such a transformation may be obtained.

Thus the ears of wheat, sculptures on the tombs of the kings who ruled in those far-off ages, tell us that behind the nations called the oldest, stretch long vistas of time, and that Egyptian, Babylonian, and Hindoo civilization are but things of yesterday compared to the countless ages that went before.

And so the fossil found in the rock may tell its story; and, as its form differs from the living animal, we may judge of the long period of time that must have elapsed, and what vital difference of conditions must have occurred to bring about the change.

These views of Lamarck were also held in some degree by Buffon and other naturalists of the period, but they were never popularly accepted, and it remained for another generation to reap the harvest of the seed thus sown.

Chief among those who have made the subject prominent in the nineteenth century was Charles Darwin, who was born in Shrewsbury, England, in 1809. Darwin’s early love for natural history was developed in a marked degree during his college life by his study of geology, which first led him to take an interest in the succession of life on earth, and it was while he was pondering over the views of the opposing schools of geology that he began to seriously think of the great questions of the development of different forms of animal life.

His love for natural science brought him into notice; and, when he was but twenty-two years old, he was appointed naturalist of a government surveying party which intended visiting the coasts of South America and the islands of the Pacific.

This voyage occupied five years, and left Darwin with no choice of a profession, as his special work was from that time as much a necessity of his life as his love for it was deep and abiding. The Western World fascinated the young naturalist, and all the varying forms of tropical life, from the gigantic palms to the flowers which sprinkled the earth like stars, and from the huge fossils, which told of other ages, to the tiny lizards which gleamed like fire-flies in and out among the rank grass, were alike full of interest.

The collections made during this time were very important, including plants, insects, birds, reptiles, fish, fossils, and everything that could illustrate the flora and fauna of South America, Australia and the Pacific islands, and the results of the voyage were given to the world in a book called the "Zoology of the Voyage of the Beagle," of which Darwin was the editor.

The cruise of the Beagle may be said to have formed the education of Darwin as a naturalist, an education wider and broader than any vouchsafed to so young a naturalist before, as it included a study of the forms of life in regions practically unknown, and occurred at a period of life when the young student was not yet hampered by the fixed ideas of those in authority.