226 HOW CROPS OKOW. 



On dividing the above quantities by the number of days 

 of the respective periods, there results: 



The Average Daily Gain or Loss per Acre during 

 each Period. 



Table IY.—£retschneider. 



Dry Mutter. Water, 



1st Period, 22 lbs. Gain. 87 lbs. Gain. 



Loss. 



4. — Table III, and especially Table IV, show that the 

 gain of organic matter in Bretschneider's oat-crop went 

 on most rapidly at or before the "time of blossom (accord- 

 ing to Arendt at the time of heading out). This was, then, 

 the period of most active growth. Afterward the rate of 

 growth diminished by more than one-half, and at a later 

 period increased again, though not to the maximum. 



Absolute Quantities of Carbon, Hydrogen, Oxy- 

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

 oat-crop at the conclusion of the several periods {Jbs. 



'per acre) : 



Table V.—Sretsehnelder. 



Carbon. Ifydrogen. Oxygen. Nitrogen, Ash,* 



1st Period, 593 80 455 46 110 



2d & 3d " 2,137 286 1,675 122 263 



4th " 2,600 343 2,043 150 291 



6th " 3,229 406 2,713 167 372 



Amounts of Carbon, Hydrogen, Oxygen, Nitre, 

 gen, and Ash-ingredients assimilated by the oat-crop 

 during the several periods. "Water of vegetation is not 

 included {lbs, per acre) : 



Table Yl.—Bretschneider, 



*In Bretschneider's analyses, "ash" signifles the residue left after 

 carefully burning the plant. In ATendt.s investigation the sulphur 

 and chlorine were determined in the unbumed plant. 



