Properties and Activities of Living Protoplasm 97 



When certain parts of a living organism have been impaired or de- 

 stroyed, frequently other parts, through the inherent process of self- 

 regulation, take on compensatory reactions or activities in order to re- 

 gain a complete, well-balanced normality. Examples of such activities 

 are as follows: If one human kidney is diseased or destroyed, the other 

 adjusts or compensates to attempt to do the work of both. If tissues 

 or organs require more oxygen, the circulatory system attempts to circu- 

 late the extra amounts necessary. The quantity and quality of the 

 digestive juices are regulated within certain limits by the variations in 

 the diet of the organism. When emergencies arise, increased energy is 

 required. Consequently, larger quantities of foods in various parts of 

 the organism are liberated and changed to meet the extra demands. 



Through some internal recording or regulation, the efforts and reac- 

 tions of living organisms frequently serve as a kind of experience by 

 which they are led to avoid similar, undesirable kinds of actions in the 

 future and attempt to repeat the desirable and successful ones. This 

 makes for the preservation of the individual, as well as the race, in the 

 struggle for existence. 



VII. ORGANIZATION AND INDIVIDUALITY 



All parts of living organisms are so integrated that the whole thing is 

 a unit or an individual. Individuality is due to the fact that some one 

 part of the organism which is most active presides or predominates over 

 the less active parts and thus keeps them all in organized subordination. 

 In each living organism there are ( 1 ) interdependence and systematic cor- 

 relation of parts, (2) a variable susceptibility to environmental influ- 

 ences, (3) inherent self-regulatory tendencies, and (4) a centralized con- 

 trol. All of these working harmoniously together make the living or- 

 ganism a unified individual rather than a mere inchoate mass of sepa- 

 rate and unrelated parts. 



Many, if not all, living organisms are organized on one or more axes 

 along which the various tissues, organs, and physiologic units are ar- 

 ranged in a somewhat graded series, the more active being at the con- 

 trolling apical region, and the less active at the opposite end. Between 

 these two regions is a graded series of decreasing activities extending 

 from one end to the other on this imaginary line or axis. This arrange- 

 ment of structures and physiologic units is known as the axial gradient 

 which to a great extent determines the organization of the organism as 



