M. M. SWANN 



for any given cell type, and this could readily be explained as a slowing up of one or 

 other mechanism. 



In an attempt to follow the implications of this idea, the concept of differing 

 'priorities' for the cell's supply of energy is introduced. It is suggested on purely bio- 

 logical grounds that the first priority is likely to be for maintenance, with growth 

 second and division third. If so, a reduction in the available supply of energy, 

 whether caused by anaerobiosis, inhibitors, or partial starvation of energy-providing 

 foodstuffs, should lead to a slowing down of division before it leads to a slowing down 

 of growth. Such unfavourable conditions should therefore result in an increase of 

 cell size (dry weight) . Such evidence as is available suggests that this is the case. 



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