Page:Popular Science Monthly Volume 33.djvu/79

Rh selection" by a mind deliberately divesting itself of its own higher faculties, and choosing in consequence to exert only those which are simple and almost infantile. The question naturally arises. What is the most universal peculiarity and distinction of organic forms? When we get rid of ourselves, when we stand outside of our own anthropocentric position, and consult only the faculties which are most purely physical, we shall be compelled to reply that the great specialty of organic forms is the "differentiation of their outside from their inside." They have all an outside and an inside, and these are different. They begin with a cell, and a cell is a blob of jelly with a pellicle or thin membrane on the outside. Do we not see in this the mechanical action of the surrounding medium? The skin may come from a chill on the outside, or the pressure of the medium. Does not a little oil form itself into a sphere in water, or a little water into a drop in air? And so from one step to another, can not we conceive how particles of protein become cells, and how one cell gets stuck to another, and the groups to groups—all with insides and outsides "differentiated" from each other, and so they can all be pressed and compacted and squeezed together until the organism is completed?

Such or such like are the images presented to enable us to conceive the purely physical view of the beginnings of life. Their own genesis is obvious. It is true that all or nearly all organisms have a skin. Most if not all of them begin, so far as seen by us, in a nucleated cell. The external wall of these cells is often a mere pellicle. It is true also that one essential idea of life is separation or segregation from all other things. This is an essential part of our ideas of individuality and of personality. If a pellicle or skin round a bit of protein be taken as the symbol of all that is involved in this idea of life, then "outness" and "inness" may be tolerated as a very rude image of one of the great peculiarities of all organic life. It may even be regarded as a symbol of the thoughts expressed in the solemn lines—

 "Eternal form shall still divide The eternal soul from all beside."

But if "outer" and "inner" are used to express the idea of some essential mechanical separation between different parts of the same organism, so that one part may be represented as more the result of surrounding forces than another—then this rude and mechanical illustration is not only empty, but profoundly erroneous. The forces which work in and upon organic life know