There is nerve-protoplasm, brain-protoplasm, bone-protoplasm, muscle-protoplasm, and protoplasm of all the other tissues, no one of which but produces only its own kind, and is uninterchangeable with the rest. Lastly, we have the overwhelming fact that there is the infinitely different protoplasm of the various infinitely different plants and animals, in each of which its own protoplasm, as in the case of the various tissues, but produces its own kind, and is uninterchangeable with that of the rest.
It thus appears that the character of Protoplasm, far from making it easier to conceive the mechanical production of living things, does but immensely aggravate the difficulty. As Sir William Thiselton-Dyer avows: "I do not see even the beginning of a materialistic theory of protoplasm." And Haeckel's idea that we shall succeed in creating organic life does not commend itself to such an authority as Sir Henry Roscoe:
It is true [he says][101] that there are those who profess to foresee that the day will arise when the chemist, by a succession of constructive efforts may pass beyond albumen, and gather the elements of lifeless matter into a living structure. Whatever may be said of this from other standpoints, the chemist can only say that at present no such problem lies within his province. Protoplasm, with which the simplest manifestations of life are associated, is not a compound, but a structure built up of compounds. The chemist may successfully synthesize any of its component compounds, but he has no more reason to look forward to the synthetic production of the structure than to imagine that the synthesis of gallic acid leads to the artificial production of gall-nuts.
And M. de Quatrefages thus sums up the conclusions at which he arrives from minute study of the lowest forms of life:[102][{63}]
I make bold to affirm that the deeper Science penetrates into the secrets of organization and phenomena, the more does she demonstrate how wide and how profound is the abyss which separates brute matter from living things.
The other point requiring notice is crystallization. Inorganic matter, as we know, can build up crystals, the wonderful structure of which results from the molecular properties of the substance crystallized. Why then, some would ask, may not matter in the same manner produce Protoplasm?
But, in the first place, this, as we have heard, is what it is never found to do. Crystals we can produce at pleasure, in what quantity we will. But all efforts have not yet succeeded in obtaining the most minute speck of living matter. Moreover, nothing can be more widely different from organic structures than crystals. The latter are always mathematical, the former never: the latter grow by outside accretion, of the one kind of particles whereof they consist: the former by absorption and assimilation of various foreign substances: the latter are wholly independent of anything like an ancestor: for the former an ancestor is in our experience indispensable: crystals can be dissolved and recrystallized: living matter once destroyed can never be reconstituted. Above all, the particles incorporated in the crystal are absolutely quiescent, so far as any portion of matter can be said to be so, no more able to change their position without external force than the bricks in a wall, while those[{64}] in living tissue at once become subject to "the whirlwind of life," involving constant change the cessation of which is death.
It is inexplicable to me [says M. de Quatrefages][103] that some men whose merits I otherwise acknowledge, should have compared crystals to the simplest living forms.... These forms are the antipodes of the crystal from every point of view.
To the same effect speaks Mr. A. R. Wallace, Mr. Darwin's associate in the discovery of the Darwinian theory. In a work expressly devoted to the vindication of that theory, Mr. Wallace declares that far from the way of evolution being made clear by Science from end to end—"there are at least three stages in the development of the organic world where some new cause or power must necessarily have come into action." And at the head of them he places that which we are now considering, writing thus:[104]