of capitalists, overseers, workers, etc., and while the great function of distribution is carried on by wholesale and retail dealers in different commodities. Meanwhile students of biology, led by Milne-Edwards's phrase, have come to recognize a parallel arrangement in a living creature; shown, primarily, in the devoting of the outer parts to the general business of obtaining food and escaping from enemies, while the inner parts are devoted to the utilization of food and supporting themselves and the outer parts; and shown, secondarily, by the subdivision of these great functions into those of various limbs and senses in the one case, and in the other case into those of organs for digestion, respiration, circulation, excretion, etc. But now let us ask what is the essential nature of this division of labor. In both cases it is an exchange of services—an arrangement under which, while one part devotes itself to one kind of action and yields benefit to all the rest, all the rest, jointly and severally performing their special actions, yield benefits to it in exchange. Otherwise described, it is a system of mutual dependence: A depends for its welfare upon B, C, and D; B upon A, C, and D, and so with the rest: all depend upon each and each upon all. Now let us apply this true conception of the division of labor to that which Prof. Weismann calls a division of labor. Where is the exchange of services between somatic cells and reproductive cells? There is none. The somatic cells render great services to the reproductive cells, by furnishing them with materials for growth and multiplication; but the reproductive cells render no services at all to the somatic cells. If we look for the mutual dependence we look in vain. We find entire dependence on the one side and none on the other. Between the parts devoted to individual life and the part devoted to species-life, there is no division of labor whatever. The individual works for the species; but the species works not for the individual. Whether at the stage when the species is represented by reproductive cells, or at the stage when it is represented by eggs, or at the stage when it is represented by young, the parent does everything for it, and it does nothing for the parent. The essential part of the conception is gone: there is no giving and receiving, no exchange, no mutuality.
But now suppose we pass over this fallacious interpretation, and grant Prof. Weismann his fundamental assumption and his fundamental corollary. Suppose we grant that because the primary division of labor is that between somatic cells and reproductive cells, these two groups are the first to be differentiated. Having granted this corollary, let us compare it with the facts. As the alleged primary division of labor is universal, so the alleged primary differentiation should be universal too. Let us see whether it is so. Already, in the paragraph from which I