COMPOSITION IN" StCCESSlVE STAGES. 227 



Relative Quantities of Carbon, Hydrogen, Oxy- 

 gen, Nitrogen (Organic Matter) and Ash in the dry 

 oat-crop, at the end of the several periods (per cent) : 



TABLE \n.Iiretsi-h neuter. 



Carbon. Hydrogen. Oxygen. Nitrogen. (Organic Matter.) Ash. 



1st Period, 46.22 6.23 35.39 3.59 91.43 8.57 



1M ,* '3d " 4S.7C. ;..->.{ 35.96 2.79 94.04 5.96 



4th " 47.91 6.33 37.65 2.78 94.67 5.33 



Mil " 4<>.s!t 5.88 39.40 2.43 94.60 5.40 



Relative Quantities of Carbon, Hydrogen, Oxy- 

 gen, and Nitrogen, in dry substance, after deducting 

 the somewhat variable amount of ash (per cent) : 



TABLE \IlI.Bret$chneider. 



Carbon. Hydrogen. Oxygen. Nitrogen. 



1st Period, 50.55 6.81 38.71 3.93 



2d & 3d " 51.85 6.95 38.24 2.86 



4th " 50.55 6.96 39.83 2.93 



5th " 49.59 6.21 41.64 2.56 



5. The Tables V, VI, VII, and VIII, demonstrate that 

 while the absolute quantities of the elements of the dry 

 oat-plant continually increase to the time of ripening, 

 they do not increase in the same proportion. In other 

 words, the plant requires, so to speak, a change of diet 

 as it advances in growth. They further show that nitro- 

 gen and ash are relatively more abundant in the young 

 than in the mature plant ; in other words, the rate of 

 assimilation of Nitrogen and fixed ingredients falls be- 

 hind that of Carbon, Hydrogen, and Oxygen. Still oth- 

 erwise expressed, the plant as it approaches maturity 

 organizes relatively more carbhydrates and less albu- 

 minoids. 



The relations just indicated appear more plainly when 

 we compare the (Jinintiti<>x of Xitrogen, Hydrogen, and 

 Oxygen, assimilated during each period, calculated upon 

 the amount of Carbon assimilated in the same time and 

 assumed at 100. 



TABLE IX. 7 



Cartiuii. Miriujfii. Hydrogen. O.rt/gen. 

 1st Period, 100 J 13.4 73.6 



2d&3d" 100 4.9 13.3 72.5 



4th " 100 6.1 12.3 100.8 



5th " 100 2.6 10.6 100.5 



