CHARACTERISTICS OF LIVING MATTER ii 



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 metabolic 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 Nervous System from 

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

 p. 12. 



