than any one individual possessed, even the strongest. It is owing to this united strength that the defenseless plant-eaters can ward aff rapacious animals. It is only by means of this unity that some animals are able to protect their young.
A second advantage of sociability arises from the fact that where animals live socially, there is a possibility of the division of labor. Such animals send out scouts or place sentinels whose object it is to look after the safety of all, while others spend their time either in eating or in plucking, relying upon their guards to warn them of danger.
Such an animal society becomes, in some respects, a unit, a single organism. Naturally, the relation remains much looser than the cells of a single animal body; nevertheless, the group becomes a coherent body, and there must be some power that holds together the individual members.
This power is found in the social motives, the instinct that holds them together and causes the continuance of the group. Every animal must place the interest of the entire group above his own; it must always act instinctively for the advantage and maintenance of the group without consideration of itself. As long as the weak plant-eaters think of themselves only and run away when attacked by a rapacious animal, each one minding his life only, the entire herd disappears. Only when the strong motive of self-preservation is suppressed by a stronger motive of union, and each animal risks its life for the protection of all, only then does the herd remain and enjoy the advantages of sticking together. In such a case, self-sacrifice, bravery, devotion, discipline and consciousness must
