As a matter of fact, among the many forms of matter which exist on this earth of ours, the only clear-cut division is between the organic and the inorganic. The primary characteristic which distinguishes a living creature from inanimate objects about it is, in the words of Arthur Dendy, its power of “reacting toward its environment in such a manner as to conduce to its own well-being; of controlling not only its own behaviour but also the behaviour alike of its fellow creatures and of inanimate objects, in its own interests, thereby maintaining its own position in the universal struggle for existence.” If this, then, is the one characteristic which distinguishes all terrestrial life, it follows that all creatures from the unicellular protoza to man himself are intimately related, are all part and parcel of the same system, are recognizable by differences in degree but not in kind, and are all interesting manifestations of that mysterious thing we call life. No creature lives or dies to itself. The correlation of organisms in Nature is similiar to the correlation of organs in individual plants and animals. If the reader will but face this fact, he will approach the study of Nature with a new reverence. He will recognize the oneness and kinship of all life. It is largely the object of this book to explore the inner recesses of breathing and thinking plantdom--to take the reader beyond the limits of text-book botany into regions of sympathetic insight--to show how even human arts and sciences are unchangeably bound up with the lives and hopes of the grasses and flowers. To do this comprehensively, it has been thought wise not only to indicate how plants think and act but to incorporate a broad general history of their race stretching back to their first appearance on the planet and carried forward to the Burbank creations. With this knowledge in hand, we are better equipped to approach that fascinating realm which touches on the intelligence, the spirituality, the mysticism, the psychic phenomena, the higher life of plants. In all this, the manifest independence of plant life and purpose is convincingly apparent. The plants have their own lives to lead and their own evolutionary processes to carry on. They completed the conquest of the earth long before the first human being appeared on its surface. Out of approximately a hundred thousand species of flowering plants, it has been estimated that only two hundred and forty-seven render direct and important service to man, and of these, only about fifty-four are utilized by him to any great extent.