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The animal body, if it be composed of many cells, follows a different architectural plan; the compact nature of its food, and the yielding nature of its cell-walls, result in a form of structure consisting essentially of tubular or spherical masses of cells arranged concentrically round the food-cavity.
But my son Francis, after making and examining sections, could nowhere find that the cell-walls had been broken down or that the epidermis had been penetrated. When the section passed through the whitish dots, the grains of chlorophyll were seen to be more or less discoloured, and some of the palisade and mesophyll cells contained nothing but broken down granular matter.
But they live chiefly on half-decayed leaves; and these would be useless to them unless they could digest the cellulose forming the cell-walls; for it is well known that all other nutritious substances are almost completely withdrawn from leaves, shortly before they fall off.
The hazy semitransparency of the embryonic tissues, the halos, the granules, the globules, the cell-walls, the delicate membranous expansions, the vascular webs, are expressed with purity, softness, freedom, and a conscientiousness which reminds us of Donne's microscopic daguerreotypes, while in many points the views are literally truer to nature, just as a sculptor's bust of a living person is often more really like him in character than a cast moulded on his features.
No chemical change has yet intervened to break down their cell-walls, or interfere with the occupations assigned them. The machinery that ran their looms is stopped that is all. The invisible shuttles have ceased to ply the meshes of their tangled webs are broken the more delicate threads of song are snapped in sunder, but the bioplastic spinners and weavers are all there.
We may therefore conclude that they contain carbonate of lime. If the cells are immersed in a very little acid, they become more transparent, look like ghosts, and are soon lost to view; but if much acid is added, they disappear instantly. After a very large number have been dissolved, a flocculent residue is left, which apparently consists of the delicate ruptured cell-walls.
The very admission that the bioplast spins, makes it an organism, and not mere structureless matter. For the first thread it spins is manifestly for its own covering or the ornamentation of its own cell-walls. And to speak of these as "structureless matter" is to confound all scientific sense, as well as meaning. The third objection to Mr.
Either way the action of the medium causes its formation; and either way the many varied and complex differentiations which developed cell-walls display, must be considered as originating from those variations of this physically-generated covering which natural selection has taken advantage of.
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