70 The Unity of the Organism 



duce and direct the movements, we will hear him state in his 

 own words. It is "a result of the directive activity of the 

 definite and always similar developmental processes, . . . 

 therefore of those conditions which determine not only the 

 form of a body part, or organ, but also the transportation 

 and definitive emplacement of the separate particles. I re- 

 tain for this the expression 'form-conditions' used by me 

 several years ago."^^ Obviously this statement by Goette 

 carries us far beyond the bounds of germ-layers or even of 

 sex-cells and hereditary substance. 



To the numerous biologists who w^ould refuse to accept 

 Goette's "directing activity of the developmental process" 

 and his "Form-conditions" as an explanation of the mi- 

 gration of the sex-cells in the hydromedusae, because they 

 are vague and "unanalysed" conceptions, I put the question: 

 Are Weismann's conceptions of a wholly independent power 

 of movement possessed by the cells, and a determination of 

 the route followed by them as an innate instinct of their an- 

 cestral home possessed by the cells, less vague and more 

 satisfactory because of the results of such an "analysis".^ 

 Let it be granted for a moment that the cells perform their 

 journeys by activities wholly their own, that they are com- 

 petent both to travel and to reach the end proper to them. 

 What then about the elements which enter into their make- 

 up, for surely no one w^ould contend for a moment that they 

 are without elements ? Shall we conceive that in moving they 

 do so by making use of their elements or parts in such fash- 

 ion as may be necessary to enable them to accomplish their 

 journeys? Or shall we deny to the cells as such the power 

 of using their parts, but conceive that the parts are the 

 real seat of power — that in reality they move the cells instead 

 of being moved by the cells? If we accept the latter alter- 

 native, as in consistency with the elementalist standpoint we 

 should have to, we shall be committed to either a never- 

 ending though ever-vanishing series of biological elements. 



