VITAL ACTION VS. NATURE-ACTION 207 



asymmetrical modifications, or unlike poles, oral and 

 aboral, and with peculiar zonal and radial growths. 

 Some phases of these bodily specializations are doubt- 

 less correlated with the peculiarities of special environ- 

 ments, or modes of life, and above all with the fact 

 that the external environment, as a whole, is never 



FIGURE 3. DIAGRAM OF THE RADIAL ARCHITECTURAL PLAN (Coelenterate, 

 or jelly-fish, t, tentacle; s.o., sense organ (eye or ear); g, germ cells; 

 m.a. t common opening for mouth and anus; n.m.r., neuro-muscular ring. 



either homogeneous or symmetrical. It has a perma- 

 nent asymmetry and a gradient differentiation of its 

 own, in four important respects: (i) as regards the 

 lines of gravity; (2) the source of light; (3) the rota- 

 tion of the earth on its axis, and (4) the marked dif- 

 ference between its underlying and overlying media, 

 or solid earth below and atmosphere above, with their 

 consequent effects on circulation and diffusion. 



These asymmetrical, gradient constants of the outer 

 world are the same ones which play such an impor- 



