April 14, 1916] 



SCIENCE 



521 



ences in metabolic rate may determine the 

 production of different substances. On the 

 basis of these and other lines of evidence, 

 I believe that we are fully justified in 

 maintaining that purely quantitative dy- 

 namic differences, i. e., differences in meta- 

 bolic rate may and do serve as the starting 

 point of very great qualitative differences, 

 both in structural constitution and char- 

 acter of metabolic reaction. In short, both 

 physiological and biochemical facts sup- 

 port the view that a metabolic gradient is 

 adequate to account for the beginning of 

 differentiation along a physiological axis, 

 and the burden of proof must rest on those 

 who maintain that it is not. Of course the 

 character of the qualitative differences 

 which arise from the quantitative, must 

 depend on the specific constitution of the 

 protoplasm concerned. 



It is evident that as soon as orderly dif- 

 ferences arise chemical transportative cor- 

 relation between the different parts must 

 play a very important role in determining 

 the character and course of further devel- 

 opmental changes, but it is also evident 

 that such chemical correlation can not exist 

 until differences exist nor can it be orderly 

 or definite in character unless the differ- 

 ences on which its existence depends are 

 orderly and definite. The conception 

 which I have presented is an attempt to 

 show how these orderly differences arise 

 and make possible chemical correlation. 



To sum up, physiological individuality 

 depends fundamentally and from the be- 

 ginning on the transmission of dynamic 

 excitations and not upon the transporta- 

 tion of substances. Transportative corre- 

 lation, while of great importance, is a 

 secondary factor, playing a role in deter- 

 mining the course and character of develop- 

 ment, but not in determining the existence 

 of an individuality. And, furthermore, 

 the facts indicate that a definite orderly 



transmissive correlation can originate only 

 in a region of relatively high metabolic 

 rate determined in the final analysis by 

 factors external to the protoplasm con- 

 cerned. Transmission from such a region 

 of high rate determines a metabolic gradi- 

 ent together with its protoplasmic corre- 

 lates, and so constitutes a physiological 

 axis, a physiological individuality in its 

 simplest form. 



In conclusion I wish to point out the 

 fundamental similarity from this point of 

 view between the physiological and the so- 

 cial individual. The organism has often 

 been compared to an ordered community of 

 human beings or a state, but in these com- 

 parisons the question as to the factor or 

 factors which determine the orderly char- 

 acter of the organism has usually been ig- 

 nored. In the social individual it is au- 

 thority or government which integrates 

 the human units into an orderly whole. I 

 have attempted to show that an authority 

 or government of a simple dynamic kind is 

 the primary integrating factor in the 

 physiological individual. There are, more- 

 over, certain rather fundamental similari- 

 ties which are more than far-fetched fanci- 

 ful analogies between government in the 

 organism and in the social individual. 



In its simple primitive forms, such as 

 tribe, clan, etc., the social individual is 

 integrated by the authority of a dominant 

 person or perhaps of a group and this au- 

 thority consists fundamentally in what we 

 call brute force, which is something not 

 very different from high metabolic rate in 

 the organism. The dominance of the rul- 

 ing personality depends, not upon the 

 transportation of material from him to 

 other members of the community, but upon 

 the transmission of personal influence, and 

 the size of the primitive social individual 

 depends on the extent to which he is able 

 to make this influence felt, i. e., on his per- 



