To keep sheep, to shear, and card, and spin, and weave, and cut, and sew—all these processes require a stationary group of still longer standing; they are social processes. A man alone can catch another animal, can “eat his fat and wear his hair”; but the baker and the tailor are slowly evolved social functionaries. Everywhere we see the present proof that the wants of man are not supplied by his own efforts and cannot be; that his life processes are essentially collective. Now let us approach these facts from behind, watch their inception and growth, and see how unavoidable is the conclusion. The life of any creature is primarily dependent on the regular renewal of its constituent particles. The process of living uses up the materials lived in. Living involves dying, and to postpone the dying the structure is continually supplied with fresh materials. This continuous supply of fresh materials we call nutrition. It is an increasingly elaborate process, with “many a slip ’twixt the cup and the lip”; and the main line of organic evolution is in development of these nutritive processes. Conditions of the environment modify a creature, as in hide and hair; conditions of inter-animal competition modify him, as in horns and stings; conditions of reproduction modify him, developing an elaborate physical mechanism and a more elaborate scheme of decoration; but the most distinctive modification of a creature is that produced by its nutritive conditions. “Order Mammalia,” with all its towering superiority, is founded merely on a new way of feeding the baby. The food supply of the world is subject to fluctuating influences—climatic, geographic, and other; and as we watch the widening panorama of animal forms changing and growing up the ages, we see the whole procession to be moving always in one line—in pursuit of its dinner. We think of our dinners as a pleasing series of events, but we do not appreciate their awful importance. The life of any creature absolutely depends on getting together a certain group of chemical constituents and keeping them reinforced. While those constituents, massed in certain proportions, are cunningly poured through a certain small orifice called a mouth, the creature lives. A procession of dinners passing a given point—that is the physical condition of life. _We_ are the given point. If the procession goes another way—or stops awhile—“we” cease to live.