Page:Popular Science Monthly Volume 43.djvu/489

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APART from those more special theories of Prof. Weismann I lately dealt with, the wide acceptance of which by the biological world greatly surprises me, there are certain more general theories of his—fundamental theories—the acceptance of which surprises me still more. Of the two on which rests the vast superstructure of his speculation, the first concerns the distinction between the reproductive elements of each organism and the nonreproductive elements. He says:

"Let us now consider how it happened that the multicellular animals and plants, which arose from unicellular forms of life, came to lose this power of living forever.

"The answer to this question is closely bound up with the principle of division of labor which appeared among multicellular organisms at a very early stage. . . .

"The first multicellular organism was probably a cluster of similar cell?, but these units soon lost their original homogeneity. As the result of mere relative position, some of the cells were especially fitted to provide for the nutrition of the colony, while others undertook the work of reproduction" (Essays upon Heredity, p. 27).

Here, then, we have the great principle of the division of labor, which is the principle of all organization, taken as primarily illustrated in the division between the reproductive cells and the nonreproductive or somatic cells—the cells devoted to the continuance of the species, and the cells which subserve the life of the individual. And the early separation of reproductive cells from somatic cells, is alleged on the ground that this primary division of labor is that which arises between elements devoted to species-life and elements devoted to individual life. Let us not be content with words but look at the facts.

When Milne-Edwards first used the phrase "physiological division of labor," he was obviously led to do so by perceiving the analogy between the division of labor in a society, as described by political economists, and the division of labor in an organism. Every one who reads has been familiarized with the first as illustrated in the early stages, when men were warriors while the cultivation and drudgery were done by slaves and women; and as illustrated in the later stages, when not only are agriculture and manufactures carried on by separate classes, but agriculture is carried on by landlords, farmers, and laborers, while manufactures, multitudinous in their kinds, severally involve the actions

  1. A postscript to the essay on The Inadequacy of "Natural Selection."