70 Indications of a Central Zone of Development 



general law of organic development, are phenomena 

 which indicate in their turn that this centroepigenesis 

 with ramifying, independent networks for the distribu- 

 tion of nervous energy, is also in harmony with the most 

 general biologic phenomena. 



One could always bring forward the objection that it 

 is difficult to conceive how this series of energies acting 

 one after the other, all upon the same point of the de- 

 veloping organism, could give rise to a series of dynamic 

 systems of distributions as complex as we must neces- 

 sarily suppose those to be which constitute the successive 

 stages of ontogeny. To dissipate all doubts in this mat- 

 ter one may draw attention to the following simple 

 hydro-dynamic experiment. 



Let us imagine a very large cylindrical glass container 

 almost filled with water, and having a hole at a selected 

 point in the bottom of it. By means of a suitable force 

 pump let us make more water enter the vessel through 

 this hole with a velocity varying from one moment to 

 another. To make the idea clear and the phenomenon 

 more intelligible let us suppose that the velocity varies 

 sharply each second, sometimes increasing, sometimes 

 diminishing very considerably. On account of the great 

 amount of water already contained in the vessel, the 

 series of successive systems of very complex currents 

 which will be produced each moment by the incoming 

 water, whose newly added mass interpenetrates and dis- 

 places the other in a manner which we can make appar- 

 ent in part by previously coloring the water to be injected, 

 will depend on the entire series, and exclusively on the 

 series, of different velocities with which the water is 

 forced into the container. 



A given series of dynamic actions, qualitatively alike 



