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Updated: May 2, 2025
If, however, this interval is observed at sunrise or sunset, it is seen to be not quite so structureless as it appears under different conditions, for a number of mounds and large humpy swellings, with low hills and craterlets, extend across it, and occupy a position which we are justified in regarding as the site of a section of the rampart, which, from some cause or other, has been completely destroyed and overlaid with the material, whatever this may be, of the Mare Nectaris.
Schwann and his immediate followers, while recognizing that the bodies of animals and plants were composed of cells, were at a loss to explain how these cells arose. The belief held at first was that there existed in the bodies of animals and plants a structureless substance which formed the basis out of which the cells develop, in somewhat the same way that crystals arise from a mother liquid.
Haekel says of the Monera: "The Monera are the simplest permanent cytods. Their entire body consists of merely soft, structureless plasm. However thoroughly we may examine them with the help of the most delicate reagents and the strongest optical instruments, we yet find that all the parts are completely homogeneous.
We may call it the Blastaea. Its body consisted, when fully formed, of a simple hollow ball, filled with fluid or structureless jelly, with a wall composed of a single stratum of ciliated cells. There were probably many genera and species of these blastaeads in the Laurentian period, forming a special class of marine protists.
Since then our knowledge of the formation and history of these cells has been continually growing. The size of cells varies, but as a rule they are very minute. They consist of what is termed protoplasm. At one time it was supposed that protoplasm was structureless. Now it is known that the protoplasmic cell contains a nucleus and a surrounding body.
We conclude, therefore, that the small, structureless, impregnate ovum from which we have each one of us sprung, has a potential recollection of all that has happened to each one of its ancestors prior to the period at which any such ancestor has issued from the bodies of its progenitors provided, that is to say, a sufficiently deep, or sufficiently often-repeated, impression has been made to admit of its being remembered at all.
The ultimate elements of which the body is composed consist of "masses of living matter," microscopic in size, of a material commonly called protoplasm. In its simplest form protoplasm appears to be a homogeneous, structureless material, somewhat resembling the raw white of an egg.
Let us suppose that this "structureless" morsel of protoplasm is, for all its "structurelessness," composed of an infinite number of living molecules, each one of them with hopes and fears of its own, and all dwelling together like Tekke Turcomans, of whom we read that they live for plunder only, and that each man of them is entirely independent, acknowledging no constituted authority, but that some among them exercise a tacit and undefined influence over the others.
Whether the appropriating agent be cell or nucleus, or a structureless solid like the intercellular substance of cartilage, the fact of its presence determines the separation of its proper constituents from the circulating fluid, so that even when we are wounded bone is replaced by bone, skin by skin, and nerve by nerve.
Each organized thing commences as an almost structureless mass, and reaches its ultimate complexity by the establishment of distinctions upon distinctions, by the divergence of tissues from tissues and organs from organs. Here, then, we have yet another biological law of transcendent generality.
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