VITAL ACTION VS. NATURE-ACTION 209 



Some of these inherent obstacles to progress are 

 manifestly of a purely physical or economic charac- 

 ter: (i) the presence of a common alimentary entrance 

 and exit which creates confusion and prevents unin- 

 terrupted linear streaming, serial treatment, and 

 graded distribution of alimentary materials; (2) the 

 lack of internal diversity, due to the fact that in a typ- 

 ical radiate, or in a truly spherical body, there is the 

 maximum volume relative to surface, and the minimum 

 diversity in internal relations. Every point on the 

 same circumference is potentially like every other point 

 on it, and for every point on a given radius there is a 

 homologous point, under like conditions, on every other 

 radius; (3) spherical bodies offer excessive resistance 

 to locomotion and internal exchange; and (4) a radial 

 arrangement of receptors and affectors is not capable of 

 a highly discriminating response to the agencies of the 

 outer world. 



With growth and increased demands, these disa- 

 bilities increase so that, ultimately, equitable convey- 

 ance, to meet all the varied requirements of supply and 

 demand, becomes impossible. 



XI. Spiral Growth and False Radial Symmetry 



If this radially symmetrical system, for any reason, 

 becomes structurally unbalanced, it may lead to some 

 form of spiral growth, which cannot again attain a 

 balanced symmetry, except the ends unite in the same 

 plane to form a ring. This may, in effect, then give 

 rise to a false, or secondary, radial type with the same 

 disabilities as before. 



Spiral growth is common in the great class of mol- 



