323 HOW CEOPS GBOW. 



P2O,. 



In T Samples of Eye-kernel by Fehling & Faiszt 1 : 1.97—3.06 



" 11 ' Mayer 1:2.04—2.38 



" 5 " " " Bibra 1:1.68—2.81 



" 6 ' Siegert 1:2.36—2.% 



" 28 " " " the extreme range was from 1:1.68—3.06 



" 2 " " Wheat-kernel by Fehling & Faiszt 1 : 2.71—2.86 



" 11 " " " Mayer 1:1.83—2.19 



" 2 " " " Zoeller 1:2.02—2.16 



" 30 " " " Blbra r 1:1.87—3.55 



" 6 " " " Siegert 1:2.30—3.33 



" 51 " " " the extreme range was from — 1:1.83—5.55 



Siegert, who collected these data {Vs. St., Ill, p. 147), 

 and who experimented on the influence of phosphatic and 

 nitrogenous fertilizers upon the composition of wheat and 

 rye, gives as the general result of his special inquiries that 

 Phosphoric acid and Nitrogen stand in no constant rela- 

 tion to each other. Nitrogenous manures increase the per 

 cent of nitrogen and diminish that of phosphoric acid. 



Other Relations. — All attempts to trace simple and 

 constant relations between other ingredien-fcs of plants, 

 Tiz., between starch and alkalies, cellulose and silica, etc., 

 have proved fruitless. 



It is much rather demonstrated that the proportion of 

 the constituents is constantly changing from day to day as 

 the relative mass of the individual organs themselves un- 

 dergoes perpetual variation. 



In adopting the above conclusions it is not asserted that 

 such genetic relations between phosphates and albumin- 

 oids, or between starch and alkalies, as Liebig first sug- 

 gested and as various observers have labored to show, do 

 not exist, but simply that they do not appear from the 

 analyses of plants. 



§3. 



THE COMPOSITION OF. THE PLANT IN SUCCESSIVE STAGES 

 OP GROWTH. 



We have hitherto regarded the composition of the plant 

 mostly in a relative sense, and have instituted no compar- 



