Protoplasmic Structure 53 



exactly alike, it appears that there must be a 

 definite limit to the chemical complexity of living 

 matter. We should not confuse manifoldness of 

 structure with intrinsic chemical complexity. The 

 number of variations which can be produced in 

 the cross-sectional patterns of the various units of 

 living matter by changing the connections of the 

 spirazines with one another or by adding more 

 spirazines thereto is enormous, and alterations of 

 this sort in the nuclear material of the germ cells 

 may result in all sorts of mutations during subse- 

 quent embryonic development, but the complexity 

 is in the biological significance of the pattern as a 

 whole and not in the chemical behavior of its com- 

 ponent parts. Since the maximum number of 

 atoms in the connecting complexes between two 

 adjacent spirazines is much smaller than in many 

 of the organic molecules which have been synthe- 

 sized and studied by chemists, we may confidently 

 expect that the gap which has heretofore existed 

 between chemistry and biology will soon be com- 

 pletely bridged over, and that a satisfactory mech- 

 anistic explanation for all phases of vital activity 

 will soon be forthcoming. 



In the accompanying diagrams it has been pos- 

 sible to represent the chemical structure of living 

 matter only in its statical aspect, but it should be 



