NEOPLASTIC DISEASE 



haematological diagnosis will be attached to each death 

 certificate. Without such a background, investigations are 

 not likely to be fruitful. 



5. Conclusion 



These lectures were designed primarily to present what 

 seemed to be a novel and perhaps productive way of ap- 

 proaching the problems of immunity and especially the 

 medical problems which arise when immunological responses 

 are distorted. 



The approach can, I think, be legitimately called an 

 evolutionary one and it was essentially to clarify the resem- 

 blance between cellular reactions within the body on the 

 one hand and the population dynamics of micro-organisms 

 reproducing asexually on the other, that the chapter on bac- 

 terial and viral population changes was included. Irrespec- 

 tive of what field we are considering, as the environment 

 changes the nature of the population changes, and in the 

 present state of our knowledge the changes are best under- 

 stood in terms of mutation and selective survival. 



It is universally accepted that the phenomena of immunity 

 are based on the functional activity of populations of mesen- 

 chymal cells within the body. The chief novelty of the clonal 

 selection theory is its concentration, not on what happens in 

 an individual cell, but on the way cell populations are 

 modified by the presence of antigenic determinants in their 

 environment of the body fluids. It is a Darwinian approach 

 which, pressed to its logical conclusion, demands that im- 

 munological specificity is based on a special type of differen- 

 tiation occurring in embryonic life plus a high subsequent 

 potential for somatic mutation in that region of the genome 

 (using this term in its broadest sense to cover all genetic 

 determinants, nuclear or cytoplasmic) concerned with im- 

 munologically significant pattern. 



If this interpretation of the primary formation of immune 

 pattern is in error, it should be relatively easy to devise experi- 



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