Page:Popular Science Monthly Volume 5.djvu/109

Rh yet the precise form of the human body must have been influenced by an infinite train of circumstances affecting the reproduction, growth, and health, of the whole chain of intermediate beings. No doubt, the circumstances being what they were, man could not be otherwise than he is; and, if, in any other part of the universe an exactly similar earth, furnished with exactly similar germs of life, existed, a race must have grown up there exactly similar to the human race.

By a different distribution of atoms in the primeval world, a different series of living forms on this earth must have been produced. From the same causes acting according to the same laws, the same results will follow; but from different causes acting according to the same laws, different results will follow. So far as we can see, then, infinitely diverse living creatures might have been created consistently with the theory of evolution, and the precise reason why we have a backbone, two hands with opposable thumbs, an erect stature, a complex brain, two hundred and twenty-three bones, and many other peculiarities, is only to be found in the original act of creation. I do not, any less than Paley, believe that the eye of man manifests design. I believe that the eye was gradually developed; and we can, in fact, trace its gradual development from the first germ of a nerve affected by light-rays in some simple zoophyte. In proportion as the eye became a more delicate and accurate instrument of vision, it enabled its possessor to escape destruction; but the ultimate result must have been contained in the aggregate of the causes, and these causes, so far as we can see, were subject to the arbitrary choice of the Creator.

Although Prof. Agassiz is clearly wrong in holding that every species of animals or plants has appeared on earth by the immediate intervention of the Creator, which would amount to saying that no laws of connection between forms are discoverable, yet he seems to be right in asserting that living forms are entirely distinct from those produced from purely physical causes. "The products of what are commonly called physical agents," he says, "are everywhere the same (i. e., upon the whole surface of the earth), and have always been the same (i. e., during all geological periods); while organized beings are everywhere different and have differed in all ages. Between two such series of phenomena there can be no causal or genetic connection." Living forms, as we now regard them, are essentially variable. Now, from constant mechanical causes, constant effects would ensue. If vegetable cells are formed on geometrical principles, being first spherical, and then by mutual compression dodecahedral, then all cells should have similar forms. In the Foraminifera and some other of the more lowly organisms, we do seem to observe the production of complex forms on pure geometrical principles. But from similar causes, acting according to similar laws and principles, only similar results could be produced. If the original life-germ of each creature is a