Microscopical Researches Into the Accordance in the Structure and Growth of Animals and Plants

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Sydenham Society, 1847 - 268 páginas
 

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Página 165 - The development of the proposition that there exists one general principle for the formation of all organic productions, and that this principle is the formation of cells...
Página 193 - These phenomena may be arranged in two natural groups : first, those which relate to the combination of, the molecules to form a cell, and which may be...
Página 165 - He comes to the conclusion that "the elementary parts of all tissues are formed of cells in an analogous, though very diversified manner, so that it may be asserted that there is one universal principle of development for the elementary parts of organisms, however different, and that this principle is the formation of cells.
Página 186 - The various opinions entertained with respect to the fundamental powers of an organized body may be reduced to two, which are essentially different from one another. The first is, that every organism originates with an inherent power, which models it into conformity with a predominant idea, arranging the molecules in the relation necessary for accomplishing certain purposes held forth by this idea. Here, therefore, that which arranges and combines the molecules is a power acting with a definite purpose.
Página xiii - ... distincts. — Les belles observations de M. Mirbel ont prouvé que chez les végétaux il existe un seul tissu originel, le tissu cellulaire, qui par une suite de métamorphoses, se transforme en tissu vasculaire. Par conséquent, le règne végétal est caractérisé par l'unité originel, et le règne animal par la pluralité originelle des tissus.
Página 197 - ... layer is attracted: for the nucleolus, the nucleus and cell-membrane are composed of materials which differ in their chemical properties. Such are the peculiarities of the plastic power of the cells, so far as they can as yet be drawn from observation. But the manifestations of this power presuppose another faculty of the cells. The cytoblastema, in which the cells are formed, contains the elements of the materials of which the cell is composed, but in other combinations : it is not a mere solution...
Página 188 - In physics, all those explanations which were suggested by a teleological view of nature, as "horror vacui," and the like, have long been discarded. But in animated nature, adaptation — individual adaptation — to a purpose is so prominently marked, that it is difficult to reject all teleological explanations. Meanwhile it must be remembered that those explanations, which explain at once all and nothing, can be but the last resources, when no other view can possibly be adopted; and there is no...
Página 163 - ... and the uniform principle of development in vegetable cells might be explained by the slight physiological difference of their elementary particles. The object, then, of the present investigation was to show, that the mode in which the molecules composing the elementary particles of organisms are combined does not vary according to the physiological signification of those particles, but that they are everywhere arranged according to the same laws; so that whether a muscular fibre, a nerve-tube,...
Página 39 - When this takes place, the nucleus usually appears to be formed first, and then the cell around it. The formation of cells bears the same relation to organic nature that crystallization does to inorganic. The cell, when once formed, continues to grow by its own individual powers, but is, at the same time, directed by the influence of the entire organism in such manner as the design of the whole requires. This is the fundamental phenomenon of all animal and vegetable vegetation. It is alike equally...
Página v - ... matter deposited around them formed the mass of the ganglionic globules, which were thus developed. Valentin has also observed, that after the development of nervous fibres, nuclei, elongated fibre cells, and fully developed fibres of cellular tissue are formed around them. *] Schwann's discoveries are to be ranked amongst the most important steps by which the science of physiology has ever been advanced.

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