ARCHITECTURE NATURE-ACTION 179 



In the development of a tunicate, or a barnacle, 

 for example, there is evidence of unusual internal 

 changes in the rate of growth and the character of its 

 various organs, which necessitate a return to a simpler 

 mode of life than that of its progenitors. The admin- 

 istration of its purely digestive processes is little im- 

 paired; but the secretion of thick cellulose walls, or 

 of lime-filled chiten, is developed to an extraordinary 

 degree, so that they no longer act as protective enve- 

 lopes, but as prison walls, or sinkers, or cumbersome an- 

 chors, thereby compelling these animals to adopt a ses- 

 sile, or stationary, life. Moreover the blood vessels 

 and excretory organs fail to complete the normal meas- 

 ure of their growth, greatly reducing the efficiency of 

 internal exchange; and the degeneration of the eyes, 

 brain, and locomotor organs cuts down cooperative 

 contact with the outer world, and reduces the external 

 administration of life to a minimum. 



Organic degeneration of this character, as well as 

 organic progress, involves many changes and effects 

 difficult to distinguish from one another; and some of 

 them no doubt are due to remote changes in the con- 

 structive germinal materials. But whatever the causes 

 may be, a simpler life is always a necessary result of 

 the lack of organic instruments, or a disturbance of 

 their cooperative balance; while increased freedom of 

 action is an inevitable accompaniment of better organs 

 and better organic cooperation. 



That the architectural materials used by growth 

 have far-reaching effects on the life of the organism 

 is also shown by the difference, as a whole, between 

 plant life and animal life. Animals, as a class, stand 

 on a higher cooperative level than plants because of 



