PROTOPLASMIC STRUCTURE 



Since a single spirazine, being of about the 

 diameter of a benzene ring, measures only about 

 three Angstrom units (3 X 10~ 8 cm) between the 

 centers of the atoms on opposite sides, it is evi- 

 dent that even the smallest bacteria, and all other 

 fibrous forms of living matter which are visible 

 under the microscope, must consist of aggre- 

 gates of large numbers of spirazines. The large 

 amounts of water which protoplasmic materials 

 always contain, and the rounded forms which the 

 simplest units of living matter always exhibit, 

 seem to indicate that the spirazines thereof are 

 not arranged in closely packed formation like the 

 molecules of a crystal, but rather in some sort of 

 open or spaced-apart formation. 



Chemical union between adjacent spirazines can 

 take place only through the amino, the carbonyl, 

 or the alpha carbon groups, because these are the 

 only groups that are present. Any two adjacent 

 spirazines must therefore be connected, directly 

 or indirectly, in one of the following ways : 



Amino nitrogen to amino nitrogen; 

 Amino nitrogen to carbonyl carbon; 

 Amino nitrogen to alpha carbon; 



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