VII 

 UNITIES OF LIFE 



Units of life — Simple and complex organisms — Morphological 

 and physiological individuals — Morphonta and bionta — 

 Stages of individuality: cell, person, stem — Actual and 

 virtual bionta — Partial and genealogical bionta — Meta- 

 physical individuals — Cells (elementary organisms) — Cell 

 membranes — Unnucleated cells — Plastids (cytodes and 

 cells) — Primitive cells and nucleated cells — Organella (cell 

 organs) — Cell communities (coenobia) — Tissues of histona 

 — Systems of organs — Organic apparatus — Histonal indi- 

 viduals (sprouts and persons) — Articulation of the histona 

 (metamerism) — Stems of the histona — Animal states. 



THE dissection of the body of the higher animal and 

 plant into its various organs soon prompted com- 

 parative anatomists to draw a distinction between sim- 

 ple and complex organisms. Then, when the cell-the- 

 ory developed in the course of the last half -century, 

 the common anatomic groundwork of all living forms 

 was recognized in the cell; and the conception of the 

 cell as the elementary organism led to the further belief 

 that our own frame, like that of all the higher animals 

 and plants, is a cell-state, composed of millions of micro- 

 scopic citizens, the individual cells, which work more or 

 less independently therein, and co-operate for the com- 

 mon purposes of the entire community. This funda- 

 mental principle of the modern cell-theory was applied 

 with great success by Rudolph Virchow to the diseased 

 organism, and led to most important reforms in medi- 

 cine. The cells are, in his view, independent "life-uni- 



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