The Scale of Structural Units in Biopoesis 169 



found in present-day biological structures is still tantalizingly vague in the more 

 complex regions involving the largest particles. It should serve, however, to 

 bring out the main thesis of this paper : that the existence of a whole series of 

 such structures, each with characteristically different properties, goes a long way 

 to help to explain how such an apparently almost infinitely complex organization 

 such as the cell could have been produced step by step from simpler structures 

 right back to the atomic layer, in such a way as I have described in my other 

 paper or in any other based on the same geometrical and physical conditions. 

 Although it would be a mistake to equate precisely the successively more com- 

 phcated grades of organization described here with the hypothetical temporal 

 stages of biopoesis, the two must have a rough parallelism. The formation of a 

 structure of suitable complexity is a necessary, though not a sufficient, condi- 

 tion for certain physico-chemical functions. For example, the colloidal behaviour 

 always found inside living systems, and probably absolutely necessary for them, 

 must rest on coiled and folded polymers built inside the system itself It is not 

 my place here to try to trace out these relationships in detail; this will appear 

 from many other contributions. It should be sufficient here to lay down an 

 ordered description of the various types of building blocks and bonds available 

 for biopoesis, as a guide to those who are concerned with other and more 

 dynamic aspects of it. 



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