CONCLUSIONS AND SUGGESTIONS 189 



characteristic of the dominant region and the correlatively 

 determined changes characteristic of subordinate regions. 

 It is a very significant fact that the self-determined 

 changes in animals always result, where they proceed far 

 enough, in the development of a nervous system. Of 

 course as a matter of fact the changes which occur in the 

 development of a central nervous system are not all ab- 

 solutely self-determined, for if they were all cells of 

 the nervous system would be alike. We may say, how- 

 ever, that in the animal the nervous system or its apical 

 "portion represents more nearly than any other part of 

 the body the result of self-determined progressive changes 

 in the fundamental reaction system of the species, while 

 other parts represent the result of changes determined by 

 correlation and dependence. From this point of view 

 the animal organism is fundamentally nervous system; 

 all other parts represent lower levels of metabolism and 

 independence. The central nervous system represents 

 more nearly than any other part of the individual the 

 product of the fundamental reaction system at its highest 

 level. The cephalic nervous system is, so to speak, the 

 organism at its best. 



In the plant, however, the self-determining dominant 

 region remains, at least during growth, in an undiffer- 

 entiated or relatively undifferentiated condition as the 

 growing tip, and growth and cell division are its chief 

 activities. In consequence of this condition its domi- 

 nance over other regions is slight, the degree of indi- 

 viduation in the plant remains low, and the life of the 

 plant remains simple and narrowly limited in character. 



This difference between animals and plants, in the 

 one the development of the dominant region into the 



