io THE ORIGIN OF THE NERVOUS SYSTEM 



character, that is to say, that such similarities of pattern 

 may result from the existence of similar quantitative 

 situations and relations in protoplasms which are 

 specifically very different in constitution. But in spite 

 of the fact that many different lines of evidence point 

 toward such a conception, and although many authors 

 have called attention to the quantitative character of 

 various aspects of organismic pattern, the distinction 

 between pattern and material and between the quanti- 

 tative and the specific or qualitative aspects of proto- 

 plasmic and cellular behavior has often not been 

 clearly drawn. Particularly is this true of late years, 

 during which chemical correlation, internal secretions, 

 hormones, i.e., the production, transportation and 

 effect in the organism of various substances, supposed 

 or known to be specific in their constitution and action, 

 has received so much attention that certain other 

 aspects of life have been to a large extent ignored, as 

 regards their relation to integration or pattern in the 

 organism. Nevertheless we must at least raise the 

 question, To what extent is physiological integration a 

 matter of quantitative relations in protoplasms of dif- 

 ferent specific constitution ? 



PHYSIOLOGICAL CORRELATION AS THE MECHANISM OF 



INTEGRATION 



If the organism is a physicochemical system the 

 mechanism of organismic integration and pattern must 

 consist in the factors included under what we commonly 

 call physiological correlations. Physiological or organis- 

 mic correlation may be defined as the sum total of the 

 physicochemical relations of organismic type between 



