SECTION III.
REVIEW OF THE PREVIOUS RESEARCHES—THE FORMATIVE PROCESS OF CELLS——THE CELL THEORY.
The two foregoing sections of this work have been devoted to a detailed imvestigation of the formation of the different tissues from cells, to the mode in which these cells are developed, and to a comparison of the different cells with one another. We must now lay aside detail, take a more extended view of these researches, and grasp the subject in its more intimate relations. The principal object of our investigation was to prove the accordance of the elementary parts of animals with the cells of plants. But the expression “plant-like life” (pflanzen-ahnliches Leben) is so ambiguous that it is received as almost synonymous with growth without vessels; and it was, therefore, explained at page 6 that in order to prove this accordance, the elementary particles of animals and plants must be shown to be products of the same formative powers, because the phenomena attending their development are similar; that all elementary particles of animals and plants are formed upon a common principle. Having traced the formation of the separate tissues, we can more readily comprehend the object to be attained by this comparison of the different elementary particles with one another, a subject on which we must dwell a little, not only because it is the fundamental idea of these researches, but because all physiological deductions depend upon a correct apprehension of this principle,
When organic nature, animals and plants, is regarded as a Whole, in contradistinction to the inorganic kingdom, we do not find that all organisms and all their separate organs are compact masses, but that they are composed of innumerable small particles of a definite form. These elementary particles, however, are subject to the most extraordinary diversity of
