Spikazines 31 



sulphnr atoms for every eighteen spirazines, 

 twelve triple junctions, or six polygonal compart- 

 ments as seen in transverse section. 



It will be observed that the molecular struc- 

 tures of the various triple junctions are separate 

 and distinct from one another, except for their 

 connections to the intermediate spirazines. Since 

 the spirazines themselves are all exactly alike, 

 and since they can never be separated from one 

 another by more than three or four intermediate 

 carbon atoms, it appears that there is a definite 

 limit to the molecular complexity of living mat- 

 ter. We must not confuse manifoldness of struc- 

 ture with intrinsic molecular complexity. The 

 number of variations that may be produced in the 

 cross-sectional pattern of the simplest units of 

 living matter by changing the connections of the 

 spirazines with one another is enormous, and 

 alterations of this sort in the nuclear material of 

 the germ cells may result in all sorts of mutations 

 during subsequent embryonic development, but 

 the complexity is in the biological significance of 

 the pattern as a whole, and not in the chemical 

 behavior of its component parts. Since the maxi- 

 mum number of atoms in a triple junction is much 

 less than in many of the organic molecules which 

 have been synthesized and studied by chemists, 

 we may confidently expect that a satisfactory 



