DOMAIN OF EVOLUTIONARY HYPOTHESIS 91 



Heidenheim, Pfeffer, 1 Bunge, 3 Reinke, 3 H. Driesch, 4 

 Strasburger, 5 and practically and actually by all botanists 

 and zoologists, even those who theoretically still regard 

 life as a chemico-physical process of peculiar complexity. 



Conclusions from the above. 



1. ' Life/ in the next place, is understood quite 

 generally by modern naturalists as a peculiar mode of 

 activity which we only find in the so-called organisms, 

 i.e. in systems which exteriorly are contained within 

 themselves and which consist of chemically varied and 

 structurally differentiated parts. It consists essentially 

 therein that all parts of such an organism naturally 

 act together or are active as instruments in the service 

 of the whole and on their own initiative. 



That there are natural bodies which display the 

 activity described, in contrast to others in which it 

 does not exist, is, for 01. Bernard, ' a fact to be 

 no longer disputed ' ; for 0. Hertwig, ' a fact and 



1 Pfeffer's decision in the Pfianzenphysiologie, Leipzig, 1897 and 1904, 

 we will give hereafter under the discussion on stimuli. 



2 Lehrbuch der Physiologic des Menschen, II, Leipzig, 1905, p. 7. ' In 

 the activity, therein lies the enigma of life.' 



3 Einleitung in die Theoretische Biologie, Berlin, 1901, sections 3 and 4 ; 

 also Die Weltals Tat, Berlin, 1905, chaps, xxii. and xxiii. 



4 We will treat later on of Driesch in detail. 



5 The well-known Lehrbuch der Botanik fur Hochschulen maintains this 

 opinion and establishes it excellently. 



6 01. Bernard (Lemons sur les Phenomenes de la Vie, p. 50) calls the 

 ' wonderful subordination and the harmonious co-operation of the vital 

 activities ' a fact to be no longer disputed (' le mot importe peu, il suffit 

 que la realite du fait ne soit pas discutable'). O. Hertwig (Kampf um 

 Kernfragen, etc., p. 80) : ' That the living substance ... in accordance 

 therewith (i.e. with its organization), develops peculiar ways of working, is, 

 in my eyes, a fact and no mystical conception as Verworn regards it.' 



