CONCLUSIONS AND SUGGESTIONS 185 



tentacles to normal animals. Either the plan of or^^^ani- 

 zation or the purpose of entelechy must be very (lilTcrcnt 

 in different tentacle groups on such rings. \Vc know, 

 however, that the pieces will not form rings except 

 under certain experimental conditions, and that when 

 they do not they undergo reconstitution in the usual 

 way to animals of the usual form. Evidently the 

 development of these structures on the rings results from 

 certain experimental conditions, but if simple experi- 

 mental conditions can alter the fundamental axial 

 relations in the individual, what is the necessity of the 

 postulated organization, or entelechy, or other similar 

 principle ? And does not the obhteration in Corymorpha 

 of the original axial relations and the establishment of 

 new relations in their place, by means of experimental 

 conditions whose action upon metabolism is primarily 

 quantitative (pp. 142-46), indicate that the axes them- 

 selves are primarily quantitative relations? Similarly 

 the fact that the localization of experimental reproduc- 

 tion may be determined as a resultant of dilTerent axes 

 or by a minor axis in the absence of the major axis 

 (pp. 163-68) forces us to the conclusion that the 

 different axes are fundamentally identical and therefore 

 represent quantitative relations. 



Moreover, the conception of the organic axis as a 

 metabolic gradient enables us not only to interpret, but 

 to control and to predict. In recent work on the oligo- 

 chete annelids, by Dr. Hyman, it has been possible on 

 the basis of the metabolic axial gradient to predict and 

 control experimental results, and this is possible among 

 the flatworms to an even greater degree. As regards 

 the manner in which physiological and morj^hological 



