THE SOUKCES OF THE NITROGEN OF VEGETATION, ETC. 559 



May 22. — A pipette-ful of the sulphuric-acid solution added. 



May 29. — Eight plants, 4 to G inches high; each -with four leaves, the two lower 

 yellow, the two upper green and healthy. A drop of water appears on the tip of the 

 upper leaves in the morning, but it disappears before midday, as the air is passed 

 through the shade. A pipette-ful of the phosphate-solution added. 



J une 7. — A pipette-ful of the phosphate-solution, and a pipette-ful of the sulphuric- 

 acid solution added. 



June 19. — Plants 5 to 7 inches high; two lowest leaves on each dried up; upper 

 ones yellowish green. 



June 26. — Eight plants, G to 7 inches high ; six leaves each, three lower ones dried 

 up, next two pale green, only upper central one green and healthy. Apparently at 

 limit of growth without more combined nitrogen; very much as last year without 

 nitrogenous manure. 



July 3. — A pipette-ful of the phosphate-solution, and a pipette-ful of the sulphuric- 

 acid solution added. 



July 14. — Plants 6 to 8 inches high, with six or seven leaves each; only the two 

 upper ones yellowish green ; apparent stagnation of growth. 



July 29. — Much as last; two upper leaves seem to sustain life at the expense of the 

 rest. 



August 17. — After long inactivity several plants show tendency to grow in stem. In 

 this, somewhat more like the barley than wheat of last year. Some disposition to 

 heading. 



September 7. — Still developing stem ; nodes and internodes distinctly marked. Plant 

 (a) 13 inches high, ten leaves, three nodes bare, slightly swelled at top as if heading; 

 new stem-leaves, only 2 to 3 inches long. Plants (b and c) 9^ inches high, nine leaves, 

 two or three bare nodes ; slight indication of heading. Plants (d, e, and /) 7\ inches 

 high, two bare nodes ; steins shorter, leaves eight or nine, a little longer than above. 

 Plant (g) two branches ; the first short, and dried up ; a new one formed from its base, 

 green, but only i\ inches high, with four green leaves. Plant (h), dried up stem with 

 three long leaves ; but a new green shoot with two leaves, though little growth. 

 General remark : — all lower and first-formed leaves dried up, the next yellowish, and 

 only the two upper ones green. Drops of water collect at the tips, and axils, of the 

 green leaves. The later growth obviously at the expense of the earlier. 



October 5. — Little change, except riper. Plant (a) 14 inches high, eleven leaves, 

 nearly all dried up, four bare nodes, a head with indications of seeding : (b) 10 J inches 

 high, eleven leaves, all ripe but the uppermost, three bare nodes, and indication of 

 heading: (c) 9^ inches high, nine leaves, three nodes: (d and e) 8J inches high, eleven 

 leaves each : (/ and g) 4 to 7 inches high, dead stems with eight to ten leaves each, 

 but green shoots at the base : (h) 7 inches high and seven leaves, dead ripe. 



October 24. — Weather much warmer again lately, and slight renewal of growth; 

 drops of water again appear on the green top leaves. The chief growth is further deve- 



mdccclxi. 4 o 



