CHARACTERISTICS OF LIVING MATTER 1 1 



mission of chemical and other influence between different 

 regions, and in higher organisms is effected chiefly 

 through the nervous system in co-operation with a chemi- 

 cal control exercised by special substances (hormones 

 and other metaboHc products) transported from place to 

 place in the circulation.' The possibility of these two 

 forms of integration rests ultimately on mechanical or 

 structural factors, shown in the permanence of morpho- 

 logical form and organization; hence some authors speak 

 of a mechanical integration (or correlation) in addition 

 to the other two.^ 



5. SPONTANEOUS ACTIVITY 



The chief vital phenomena classed under this head 

 are characteristic of the organism in its action as a 

 whole, rather than of its special parts, although many of 

 these are spontaneously active; e.g., the heart. They 

 are especially developed in animals, and include spon- 

 taneous activity and trains of activity (instincts) 

 directed toward the external world and having usually 

 some definite future reference; purposive and conscious 

 action, in their physiological aspect, also belong here. 

 All such characters are based upon, or presuppose, 

 the other more fundamental characters; i.e., they are 

 not general protoplasmic properties but appear at 

 a higher level of vital synthesis; hence they do not 

 form, strictly speaking, a part of our present subject- 

 matter. 



^ Cf. Sherrington's Integrative Action of the Nervous System. 



^ Cf . Child, The Origin and Development of the Ncrvot4S System from 

 a Physiological Viewpoint, University of Chicago Press (1921), chap, i, 

 p. 12. 



