COMPOSITION IS SUCCESSIVE STAGES. 239 



diminishes in quantity, being, perhaps, replaced by 

 magnesium. , 



As to potassium, no transfer is fairly indicated, except 

 from the ears. These contained at blossoming (Period 

 III) a maximum of potassium. During their subsequent 

 growth the amount of this element diminished,* being 

 probably displaced by magnesium. 



The data furnished by Arendt's analyses, while they 

 indicate a transfer of matters in the cases just named, 

 and in most of them with great certainty, do not and 

 cannot from their nature disprove the fact of other simi- 

 lar changes, and cannot fix the real limits of the move- 

 ments which they point out. 



