CHAPTER XIV 



METABOLISM or BACTERIA 



Introduction. In previous chapters we have considered 

 the relation of bacteria to their environment. We have now 

 to consider the processes inherent in the bacterial cell, that is, 

 the functions of the cell, and under this will come a discussion 

 of : i, the general character of the life processes; 2, sources 

 and expenditures of energy; and 3, respiration. The prod- 

 ucts of metabolism will be left for discussion in a separate 

 chapter. 



General Character of Life Processes. The work of the 

 living cell is determined in part by its environment, but certain 

 functions belong to the cell, and within ordinary limits are not 

 profoundly affected, except as to rate, by external conditions. 

 These general functions are: i, assimilation; 2, respiration; 

 and 3, growth and movement. To these general functions are 

 to be added the specialized activities of the cell that have been 

 acquired subsequently in the developmental history of the 

 organism. Such special functions are pigment production, 

 fermentation, disease production, etc. All of the life processes 

 of the cell are embraced in the term metabolism, which, accord- 

 ing to Vines, includes all of the chemical changes which go 



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