Chapter 32 



UNITY AND INTERDEPENDENCE 

 IN THE LIVING WORLD 



L UNITY IN THE LIVING WORLD 



The term unity can be applied in a variety of ways in the animal and 

 plant kingdoms. In such a brief space as can be devoted to this very 

 important biologic principle, the following kinds of unity will be con- 

 sidered: (A) unity within each living organism, (B) similarity of struc- 

 tures and functions between closely related species of organisms, and, 

 to a lesser degree, even in distantly related species, (C) unity and co- 

 operation between various types of living organisms of similar or dif- 

 ferent species, (D) biologic communities (associations) and successions 

 of plants and animals, and (E) dependence of all living animals and 

 most plants on photosynthesis. 



A. Unity Within Each Living Organism 



L Unity Within the Individual Cell.^ — One would easily surmise that 

 there must be unity and harmony within the protoplasm of each living 

 cell if that cell is to perform its various functions effectively and effi- 

 ciently. When this unity ceases, the cell becomes abnormal, the degree 

 of abnormality determining whether that cell will alter its structures 

 and functions or whether it will eventually die. The foundation of unity 

 and order, in the individual cell as well as in the living organism as a 

 whole, is the "inherent ability of living protoplasm to transmit dynamic 

 changes and impulses from one point to another within that proto- 

 plasm." This phenomenon results in all parts of a living organism 

 knowing what is going on in other near-by or distant regions and acting 

 accordingly. The living protoplasm also has the ability to "properly 

 integrate and harmonize these various dynamic waves of excitation so 

 that more or less complete harmony and cooperation results." It has 

 been suggested that individual cells have certain regions ("poles") 

 which are the controlling points for the activities of that particular cell. 



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