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but slight degree. The discussion as to whether lower animals have minds turns on the definition of mind, and our answer to it depends on the definition we adopt.
Most plants are sessile organisms. Each is an organic colony of cells, with the power of motion in parts but not that of locomotion. The plant draws its nourishment from inorganic nature—from air and water. Its life is not conditioned on a search for food, nor on the movement of the body as a whole. Yet the plant searches for food by a movement of the feeding parts. In the process of growth, as Darwin has shown, the tips of the branches and roots are in constant motion. This movement is a spiral squirm. The movement of the tendrils of the growing vine is only an exaggeration of the same action. The course of the squirming rootlet may be deflected from a regular spiral by the presence of water. The moving branchlets will turn toward the sun. The region of sensation in the plant and the point of growth are identical because this is the only part that needs to move. The tender tip is the plant's brain. If locomotion were in question the plant would need to be differently constructed. It would demand the mechanism of the animal. The nerve, brain, and muscle of the plant are all represented by the tender growing cells of the moving tips. The plant is touched by moisture or su nlight. It may be said, in somewhat metaphorical language, that it “thinks” of them, and in so doing the cells that are touched and “think" are turned toward the source of the stimulus. The function of the brain, therefore, in some sense exists in the tree, but there is no need in the tree for a specialized sensorium.
The many-celled animals from the lowest to the highest, bear in their organization some relation to locomotion. The animal feeds on living creatures and these it must pursue if it is to thrive. It is not the sensitive nerve tips which are to move; it is the whole creature. By the division of labor the whole body of the compound organism cannot be given over to sensation. Hence the development of sense organs different in character: one stimulated by waves of light, another by waves of sound; one sensitive to odor, another to taste; still others to contact, temperature, muscular strain, and pain. These sense organs must through their nerve fibers report to a sensorium which is distinct from each of them. And in the process of specialization the sensorium itself is subdi
vided into higher and lower nerve centers; centers of conscious thought and automatic transfer of impulse into motion. This transfer indicates the real nature of all forms of nerve action. All are processes of transfer of sensation into movement. The sensorium or brain has no knowledge except such as comes to it from the sense organs through the ingoing or sensory nerves. It has no power to act save by its control of the muscles through the outgoing or motor nerves. The mind has no teacher save the senses; no servants save the muscles.
The study of the development of mind in animals and men gives no support to the medieval idea that the mind exists as an entity apart from the organ through which it operates. This“ Klavier theory” of the mind, that the ego resides in the brain, playing upon the cells as a musician upon the strings of a piano, finds no warrant in fact. So far as the evidence goes, we know of no ego, except that which arises from the coördination of the nerve cells. All consciousness is “colonial consciousness,” the product of coöperation. It stands related to the action of individual cells much as the content of a poem with the words or letters composing it. Its existence is a phenomenon of coöperation. The “I” in man is the expression of the coworking of the processes and impulses of the brain. The brain is made of individual cells, just as England is made of individual men. To say that England wills a certain deed, or owns a certain territory, or thinks a certain thought is no more a figure of speech than to say that “I will,” “I own," or "I think." The “England” is the expression of union of the individual wills and thoughts and ownerships of Englishmen. Similarly, my "ego" is the aggregate resulting from coördination of the elements that make up my body.
That what we really know of human personality tells the whole story of it no one should maintain. It is well, however, not to ascribe to it entities and qualities of which we know nothing.
MAN’S PLACE IN NATURE
A sacred kinship I would not forego
I am the child of earth and air and sea.
Lo! these large ancestors have left a breath
Man betrays his relation to what is below him, thick-skulled, small-brained, fishy, quadrumanous quadruped, ill-disguised, hardly escaped into biped, and has paid for the new powers by the loss of some of the old ones. But the lightning which explodes and fashions planets, maker of planets and suns, is in him. On the one side elemental order, sandstone and granite, rock ledges, peat bog, forest, sea, and shore. On the other part, thought and the spirit which composes and decon
poses nature. Here they are side by side, god and devil, mind and matter, king and conspirator, belt and spasm riding peacefully together in the eye and brain of every man.-EMERSON.
The ape is this rough draft of man. Mankind have their gradations as well as the other productions of the globe. There are a prodigious number of continued links between the most perfect man and the ape.-JOHN WESLEY.
One of the most important results of Darwin's studies of the origin of species has been the complete change in the philosophical conception of man. We no longer think of the human race as a completed entity in the midst of Nature, but apart
Fig. 279.-Skulls of man and the orang-utan: 1, skull of a seven-year-old German
child; 2. skull of an Australian from Murray River; 3, skull of young orang-utan; 4, skull of a grown orang-utan. (After Wiedersheim; one-sixth natural size.)
from it, with a different origin, a different motive, a different destiny. Man is like the other species, an inhabitant of the earth. a product of the laws of life; his characters are phases in the long process of change and adaptation to which all organisms are subject. From the point of view of zoology, the human race is a group of closely allied species, or subspecies, undoubted
ly derived from a common stock, and each species in its ramifications modified by the forces and conditions included under the general heads of variation, heredity, segregation, selection, and the impact of environment precisely as species in other groups are affected. It is clear that if there is an origin of species through natural causes among the lower animals and plants, there is an origin of species among men. If homology among animals and plants is the ***"...o. o o stamp of blood relation- ...'...".”" ship, the same rule holds with man as well. Man is connected with the lower animals by the most perfect of homologies. These are traceable in every bone and muscle, in every blood vessel and gland, in every phase of structure, even including those of the brain and nervous system. The common heredity of man with other vertebrate animals is as well established as any fact in phylogeny can be. In working out the details of the origin of man, we have once more the three “ancestral documents” of biology, comparative anatomy, embryology, and paleontology. Considered structurFig. 281.-Foot skeleton of chimpanzee at left, ally, man forms a single and of man at right. (After Wiedersheim.) genus, Homo, the sole rep