TWO PATTERNS OF LIFE 17 



of food by eating it. Either the organic material is secured 

 directly from green plants, resulting in herbivorous habits, or 

 indirectly by eating the herbivorous animal. This animal way 

 of securing the necessary material for constructive metabolism 

 has brought with it many of the more obvious differences be- 

 tween plants and animals. Plants are generally thought of as 

 stationary organisms, while animals are typically capable of 

 motion. This stationary nature of plant life is the result of their 

 method of procuring food, being able to absorb air, water and the 

 needed minerals in solution without moving about in search of 

 them. To be able to move is in itself no advantage, since it uses 

 up energy and valuable food reserves as well as necessitates 

 complex tissues and organs to bring about locomotion. Con- 

 sidered in this way the inability of plants to move about is not 

 an imperfect condition in which the tree, for example, is inferior 

 to the squirrel scampering along its branches, but rather the 

 perfection of a special and satisfactory method of food-getting. 

 Since they cannot live by the absorption of inorganic materials, 

 land animals are unable to survive by rooting themselves in one 

 spot; the food they require would hardly come into their open 

 mouths while they lay in wait for it. Animal locomotion is a 

 means to an end and when an animal can get its food by standing 

 motionless it becomes as stationary as a plant; witness the seden- 

 tary animals of the sea such as corals, barnacles and sea anemones 

 which depend upon ocean currents to waft dissolved organic 

 debris or minute plants into their mouths. 



This dependence of animal metabolism upon locomotion has 

 resulted in many secondary difTerences between plants and ani- 

 mals. Animals seem more conscious of their surroundings, react 

 more directly to stimuli, and in general "feel" more obviously 

 than plants. Among the vertebrate animals this has resulted in 

 the development of complex nervous systems and, ultimately, 

 intelligence. Plants lack nervous systems and brains, quite possi- 

 bly, because they never needed them. Consciousness of one's 

 surroundings is imperative only for an organism searching for 

 food; sense organs help in locating the food; a co-ordinated 

 neuromuscular system aids in securing it. Locomotion, sensation 

 and nervous activity primarily were developed as a means to this 



