342 BEHAVIOR OF THE LOWER ORGANISMS 



knowledge or idea of that relation. We do not need any purpose or 

 idea in the mind of the organism, or any "psychoid" or entelechy, to 

 account for the change of behavior, for an adequate objective cause 

 exists. We know experimentally that the darkness or the lack of oxygen 

 interferes with the metabolic processes. This very interference is then 

 evidently the cause of the change of behavior. The organism is known 

 to be the seat of varied processes, proceeding with a certain energy. 

 When there is interference with these processes, the energy overflows 

 into other channels, resulting in changes in behavior. This statement 

 is a formulation of the facts determined by observation and experiment 

 in the most diverse organisms. It is illustrated on almost every page 

 of the present work. 



In the lower organisms the processes of metabolism are the chief 

 ones occurring, and behavior is largely determined with reference to 

 them. In higher organisms these usually retain their commanding role, 

 but an immense number of coordinated and subsidiary processes also 

 occur, and changes in behavior may be induced by interference with any 

 of these. 



The answer to our first question is then as follows : The organism 

 changes its behavior as a result of interference or disturbance in its 

 physiological processes. 



Our second question was : How does it happen that such movements 

 are produced as bring about more favorable conditions ? This question 

 we have already answered, so far as lower organisms are concerned, in 

 our general statement on page 339. The organism does not go straight 

 for a final end. It merely acts, — in all sorts of ways possible to it, — ■ 

 resulting in repeated changes of the environmental conditions. The 

 fundamental fact must be remembered that the life processes depend 

 upon internal and external conditions, and are favored by conditions 

 that are rather generally distributed throughout the environment of or- 

 ganisms. If there were no favorable conditions attainable, of course no 

 change of behavior could attain them. But the favorable conditions 

 actually exist, and if the changes of behavior continue, subjecting the 

 organism to all possible different conditions, a condition will finally be 

 reached that is favorable to the life processes. Often only a slight change 

 of behavior is required in order to bring about favorable conditions. If 

 an organism swims suddenly into a heated area, almost any change in 

 the direction of movement is likely to restore the conditions previously 

 existing. Adjustment, then, is reached by repeated changes of move- 

 ment. 



Our third question was: How does the organism select the more 

 favorable condition thus reached? This question now answers itself. 



