508 PATTEN— COOPERATION AS A FACTOR IN EVOLUTION. 



III. 



But every analysis of nature leads to the question of growth, for 

 growth is everywhere an underlying phenomenon in evolution. 

 While the basic impetus to growth is doubtless unknowable, the 

 conditions which divert, restrict, or liberate that impetus may be 

 observed and estimated. 



Our interpretation of nature is based largely on the following 

 conclusions concerning growth, which are herewith submitted, with- 

 out, for the present, further discussion or defense. 



1. Morphology is the science of form, and form is the outward 

 expression of growth. 



2. The vis a tergo in life is the product of internal cooperative 

 exchange (metabolism). 



3. Growth is profitable exchange with the outside world, or the 

 local accumulation of those agents whose demands are the impetus 

 to exchange. 



4. The rate at which growth proceeds depends: (a) on the in- 

 herent nature of the growing point, or its affinity or " demand " for 

 more materials; (b) on the distribution of supplies; (c) on the 

 capacity of the conveyers, that is, on their capacity to convey com- 

 modities to and from the growing points, or the growing points to 

 the sources of supply; and (d) on the cooperative, or creative, value 

 of the service rendered by the exchange. 



5. A local population of molecules, cells, or human beings, can- 

 not give or take more than the existing conveyers can carry ; nor can 

 exchange take place beyond the point where delivery and removal 

 can be made. 



6. The capacity of a conveyer depends on the load it can carry, 

 the distance it can be carried, and the speed. The factors, load, dis- 

 tance, and speed, vary with the commodity; and different methods 

 of conveyance are required for different commodities. In human 

 society, there is one method for the individual man, one for water, 

 coal, groceries, and ideas. In protoplasm, different methods are 

 required to convey solid and liquid foods, oxygen, and waste prod- 

 ucts, or to transmit light and other stimuli. 



7. In all such cases, the capacity of the conveyers is limited. It 



