578 Child, Driesch's harmonic equipotential systems in form-regulation. 



potential system, together with certain other features of his hypo- 

 thesis, in order to determine if possible whether the present status 

 of our knowledge actually justifies the position which he maintains. 

 I venture, therefore, to present the following consideration, in spite 

 of the risk involved of eliciting from Driesch a further expression 

 of his somewhat unflattering opinions with which I am already 

 familiar. The frequency with which the critics of this author have 

 been formed with opinions of this sort serves in some degree to 

 lessen their effect. Reference to Driesch's criticisms will be made 

 only so far as they duely concern the subject in hand. 



I. Certain of Driesch's assiuiiptions. 



The consideration of Driesch's (Driesch, 1893, 1894 etc.) 

 ideas of organic form as expressed in his earlier writings is beyond 

 the scope of the present paper, though we find here certain assump- 

 tions and views which, if accepted, lead very naturally and logicaly 

 to his later conclusions. For example, in his „Analytische Theorie" 

 (1894, p. 128) appears the following: „Man hat nun wohl die An- 

 sicht geäußert, dass jedes Stadium der Ontogenese die notwendige 

 Folge des vorhergehenden und die Ursache des folgenden sei; dieser 

 Satz ist aber nicht ohne weiteres zuzugeben, denn erstens ist die 

 Ontogenese kein einheitlicher Vorgang, sondern ist aus vielen 

 teilweise voneinander unabhängigen und in eben dieser Unabhängig- 

 keit gegebenen Vorgängen zusammengesetzt, zum andern verstehen 

 wir, wie erörtert, keinen dieser Vorgänge aus seiner Ursache auch 

 nur einigermaßen." It is of course quite true that at certain stages 

 different processes of ontogeny may proceed independently of each 

 'other, but it does not follow that each stage is not the necessary 

 result of the proceeding and the cause of the following, not is it 

 necessarily true that ontogeny is „kein einheitlicher Vorgang", at 

 least as regards the determination and initiation of the various 

 processes. Processes occurring independently at a certain stage 

 may have been initiated in direct or indirect relation to each other, 

 or they may be the results of processes so initiated. It is impos- 

 sible to determine whether ontogeny is an „einheitlicher Vorgang" 

 or not until we know it from the beginning. Present inability to 

 understand the processes from their causes may well be, and 

 doubtless is, because we know the causes only in small part. Such 

 assertions as this of Driesch's are, to say the least not at present 

 justified by the facts. 



Turning to the development of the conception of the harmonic 

 equipotential system, we find that this is likewise connected with 

 certain assumptions. In „Die Lokalisation morphogenetischer Vor- 

 gänge" (Driesch, 1899a, p. 77) it is pointed out that the locali- 

 zation of ontogenetic processes becomes a peculiar problem when 



