THE ASH OF PLANTS. 141 



tions of ash in dry matter, yielded both by the entire 



plant and by the several organs or parts. 



The following results, obtained by Norton, on the oat, 



illustrate this variation. Norton examined the various 



parts of the oat-plant at intervals of one week throughout 



its entire period of growth. He found: 



Leaves. Stem. Knots. Chaff. Grain unhusked. 



June 4 10.8 10.4 



June 11 ..10.7 9.8 



June 18 9.0 9.3 



June 25 10.9 9.1 



July 2 11.3 7.8 .. .. 4.9 



July 9 12.2 7.8 .. .. 4.3 



July 16 126 7.9 .. 6.0 3.3 



July 23 16.4 7.9 10.0 9.1 3.6 



July 30 16.4 7.4 9.6 12.2 4.2 



Aug. 6 16.0 7.6 10.4 13.7 4.3 



Aug. 13 20.4 6.6 10.4 18.6 4.0 



Aug. 20 21.1 6.6 11.7 21.0 3.6 



Aug. 27 23.1 7.7 11.2 22.4 3.5 



Sept. 3 20.9 8.3 10.7 27.4 3.6 



Here, in case of the leaves and chaif, we observe a con- 

 stant increase of ash, while in the stem there is a constant 

 decrease, except at the time of ripening, when these rela- 

 tions are reversed. The knots of the stem preserved a 

 pretty uniform ash-content. The unhusked grain at first 

 suffered a diminution, then an increase, and lastly a de- 

 crease again. 



Arendt found in the oat-plant fluctuations, not in all re- 

 spects accordant with those observed by Norton. Arendt 

 obtained the following proportions of ash : 



in 

 each of its several parts after the first examination. The 



