Page:Life and death (1911).djvu/171

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CHAPTER II.

MORPHOLOGICAL UNITY OF LIVING BEINGS.


§ 1. The cellular theory. First period: division of the organism—§ 2. Second period: division of the cell—Cytoplasm—The nucleus—§ 3. Physical constitution of living matter—The micellar theory—§ 4. Individuality of complex beings—The law of the constitution of organisms.


The first characteristic of the living beings is organization. By that we mean that they have a structure; that they are complex bodies formed of smaller aliquot parts and grouped according to a certain disposition. The most simple elementary being is not yet homogeneous. It is heterogeneous. It is organized. The least complex protoplasms, that of bacteria, for example, still possess a physical structure; Kunstler distinguishes in them two non-miscible substances, presenting an alveolar organization. Thus animals and plants present an organization, and it is sensibly constant from one end to the other of the scale of beings. There is a morphological unity.


§ 1. The Cellular Theory. First Period: Division of the Organism into Cells.


Cellular Theory. First Period.—Morphological unity results from the existence of a universal