The Growth of Social Organizations

Abstract

The relationship between an animal, for example a bird, and its young begins in essentially the same way as that between an individual and one of its organs. At the beginning the young is but an egg-cell in the body of the mother, one cell in an organ of the mother, the ovary. As soon as the egg has been fertilized, it begins to cleave and to differentiate. Through a number of complicated processes the mother’s body supplies food, and forms supporting and protecting structures, and in this way the egg-cell becomes a more or less isolated whole, an egg. When the egg leaves the body of the mother, it becomes much less dependent on the mother than it was before: food and oxygen are no longer provided by the mother. It is not completely independent, however: the mother has to brood the egg. Differentiation goes on; certain groups of cells form the skin, others the gut, others again the brain, and so on.