cognizance of ever subtler forces and movements. Memory comes into activity very early. The animal begins to learn by experience. The brain is becoming not merely a steering but a thinking organ. Morc

and more nervous material is crowded into it and detailed for its work. Wits and shrewdness are beginning to count for something in the battle. Not only the animal with the strongest muscles, but the one with the best brain survives. And thus at last the brain began to develop with a rapidity as remarkable as its long delay. Thus each higher function is called into activity by the next lower, serves this at first, and only later attains its supremacy.

And yet the advance of the different functions is not altogether successive. Muscle and nerve do not wait for digestion and reproduction to show signs of halting before they begin to advance. They all advance at once. But the progress of reproduction and digestion is most rapid at first, and it appears as if they would outrun the others. But in the ascending series the others follow after, and soon overtake and pass by them. And these lower functions, when outmarched, do not lag behind, but keep in touch with the others, forming the rear-guard and supply-train of the army. And notice that each organ holds the predominance about as long as it shows the power of rapid improvement. The length of its reign is pretty closely proportional to its capacity of development. The digestive system reaches that limit early, the muscular system is capable of indefinitely higher complexity, as we see in our hand. But the muscular system has nearly or quite reached its limit. The body had seen its day of dominance before man arrived on the globe.

But where is the limit to man's mental or moral powers? Every upward step in knowledge, wisdom, and righteousness only opens our eyes to greater heights, before unperceived and still to be attained. These capacities, even to our dim vision, are evidently capable of an indefinite, perhaps infinite, development. What, as yet only partially developed, faculty remains to supersede them? As being capable of an endless development and without a rival, may we not, must we not, consider them as ends in themselves? They are evidently what we are here for. Everything points to a spiritual end in animal evolution. The line of development is from the predominantly material to the predominance of the non-material. Not that the material is to be crowded out. It is to reach its highest development in the service of the mind. The body must be sustained and perfected, but it is not the end. The goal is mind, the body is of subordinate importance.

But if this is true, we must study carefully the development of mind in the animal. The question presses upon us; if there is a sequence of physical functions in animal development, is there not perhaps also a sequence in the development of the mental faculties? What is the crowning faculty of the human mind and how is its fuller development to be attained? Let us pass therefore to the question of mind in the animal kingdom.

CHAPTER V

THE HISTORY OF MENTAL DEVELOPMENT AND ITS SEQUENCE OF FUNCTIONS

WE have sketched hastily the development of the human body. This portion of our history is marked by the successive dominance of higher and higher functions. It is a history treating of successive eras. There is first the period of the dominance of reproduction and digestion, purely vegetative functions, characteristics of the plant just as truly as of the animal. This period extends from the beginning of life up to the time when the annelid was the highest living form yet developed. But in insects and lower vertebrates another system has risen to dominance. This is muscle. The vertebrate no longer devotes all, or the larger part, of its income to digestion and reproduction. If it did, it would degenerate or disappear. The stomach and intestine are improved, but only that they may furnish more abundant nutriment for building and supporting more powerful muscles better arranged. The history of vertebrates is a record of the struggle for supremacy between successive groups of continually greater and better applied muscular power. Here strength and activity seem to be the goal of animal development, and the prize falls to the strongest or most agile. The earth is peopled by huge reptiles, or mammals of enormous strength, and by

birds of exceeding swiftness. This portion of our history covers the era of muscular activity.

But these huge brutes are mostly doomed to extinction, and the bird fails of supremacy in the animal kingdom. "The race is not to the swift, nor the battle to the strong." All the time another system has been slowly developing. The complicated nervous system has required ages for its construction and arrangement. Only in the highest mammals does the brain assert its right to supremacy. But once established on its throne the brain reigns supreme; its right is challenged by no other organ. The possibilities of all the other organs, as supreme rulers, have been exhausted. Each one has been thoroughly tested, and its inadequacy proven beyond doubt by actual experiment. These formerly supreme lower organs must serve the higher. The age of man's existence on the globe is, and must remain, the era of mind. For the mind alone has an inexhaustible store of possibilities.

The development of all these systems is simultaneous. From the very beginning all the functions have been represented, all the systems have been gradually advancing. Hydra has a nervous system just as really as man. It has no brain, but it has the potentiality and promise of one, and is taking the necessary steps toward its attainment. But while the development of all is simultaneous, their culmination and supremacy is successive, first stomach and muscle, then brain and mind. That was not first which is spiritual, but that which is natural; and afterward that which is spiritual. But now that the mind has once become supreme, man must live and work chiefly for its higher development. Thus alone is progress possible.

But the word mind calls up before us a long list of powers. And the questions arise, Is one mode and line of mental action just as much the goal of man's development as another? Is man to cultivate the appetite for food and sense gratification just as much as the hunger for righteousness? Or is appetite in the mind like digestion in the body, a function, necessary indeed and once dominant, but no longer fitted for supreme control? Is there in the development of the mental powers or functions just as really a sequence of dominance as in that of the bodily functions? Are there older and lower powers and modes of action, which, though once supreme, must now be rigidly kept down in their proper lower place? Are there lower motives, for which the very laws of evolution forbid us to live, just as truly as they forbid a man's living for stomach or brute strength instead of brain and mind? Are these lower powers merely the foundation on which the higher motives and powers are to rise in their transcendent glory? This is the question which we now must face, and it is of vital importance.

We have come to one of the most important and difficult subjects of zoology. Let us distinctly recognize that it is not our task to explain the origin of mind, or even of a single mental faculty. I shall take for granted what many of you will not admit, that the germs of all man's highest mental powers are present undeveloped in the mind, if you will call it so, of the amoeba. The limits of this course of lectures have required us to choose between alternatives, either to attempt to prove the truth of the theory of evolution, or taking this for granted, to attempt to find its bearings on our moral and religious beliefs. I have