DYNAMICS IN EVOLUTION. 8 1 



They also make it very evident that observers have hitherto 

 allowed purely morphological considerations to becloud their 

 vision. In order to discover the meaning of the morphology 

 of the simplest organisms, their actions must be subjected to 

 the most searching analysis. These observations have proved 

 that the functions of an organism are also functions of its form. 

 It has been pretty clearly established, by what has been said 

 above, that every action of the Amoeba was followed by a mor- 

 phological change. In the belief that this same thing holds 

 good throughout the whole animal and vegetable world under 

 most complexly interacting energy-conditions, I will predict 

 what I believe will yet be possible, viz., the discovery of the 

 true causes, in detail, of the forms of all organized existences. 

 In order, however, to accomplish this end, the following will 

 first have to happen, namely, an abandonment of all hitherto 

 accepted hypotheses of inheritance, a new conception of the 

 nature of life, new views of the nature of the process of natural 

 selection, and, above all, the abandonment of all such concep- 

 tions as gemmules, biophores, pangenes, plastidules, plassomes, 

 etc., and the admission that the phenomena of life are ulti- 

 mately physical in their nature and are to be treated in detail 

 as physical problems. 



It is now my firm conviction, also, that experimental investi- 

 gation in embryology will make no solid progress until the 

 foregoing prepossessions are abandoned, or until the mischiev- 

 ous influence of such speculations and their kindred, as those 

 regarding a "germ-plasm," etc., have been entirely eradicated 

 from the minds of the present generation. In conclusion, 

 let me remark that five sciences are indissolubly connected 

 together in the study of the fundamental problems of life ; 

 these are : physics, chemistry, physiology, morphology, and 

 psychology. When each of these sciences shall have been 

 given its due weight and place in the conduct of the study of 

 life-forms, we shall begin to know what the latter really mean, 

 but not until then. 



