234 HOW CROPS GROW. 



1. The plant increases in total- weight (dry matter) 

 through all its growth, but to unequal degrees in differ- 

 ent periods. The greatest growth occurs at the time of 

 heading out ; the slowest, within ten days of maturity. 



We may add that the increase of the oat after blossom 

 takes place mostly in the seed, the other organs gaining 

 but little. The lower leaves almost cease to grow after 

 the 3d Period. 



3. Fiber is produced most largely at the time of head- 

 ing out (3d Period). When the plant has finished blos- 

 soming (end of 3d Period), the formation of fiber 

 entirely ceases. Afterward there appears to occur a 

 slight diminution of this substance, more probably due 

 to unavoidable loss of lower leaves than to a resorption 

 or metamorphosis in the plant. 



3. Fat is formed most largely at the time of blossom. 

 It ceases to be produced some weeks before ripening. 



4. Albuminoids are very irregular in their formation. 

 Ther greatest amount is organized during the 4th Period 

 (after blossoming). The gain in albuminoids within 

 this period is two-fifths of the total amount found in the 

 ripe plant, and also is nearly two-fifths of the entire gain 

 of organic substance in the same period. The absolute 

 amount organized in the 1st Period is not much less 

 than in the 4th, but in the 3d, 3d and 5th Periods the 

 quantities are considerably smaller. 



Bretschneider gives the data for comparing the pro- 

 duction of albuminoids in the oat crop examined by him 

 with Arendt's results. Taking the quantity found at 

 the conclusion of the 1st Period as 100, the amounts 

 gained during the subsequent periods are related as 

 follows: 



PERIODS. 



I. II. III. (ii.&in.) IV. (II., III. & IV.) V. 



Arendt 100 67 4G (113) 120 (233) 36 



Bretschneider .100 ? ? (165) 62 (227) 35 



We perceive striking differences in the comparison. In 



