TIEE SOURCES OF THE NITBOGEN OF VEGETATION, ETC. 553 



ammonia appears to have ceased. Second pipette-ful of ammonia-solution (same quan- 

 tity) added. 



July 11. — Two plants, 10 inches high; seven leaves each; upper ones deep green, 

 broad, and vigorous. Third pipette-ful of the ammonia-solution added. 



July 22. — Growth vigorous ; shooting out at the base of the stems. Fourth pipette-ful 

 of the ammonia-solution added. 



July 29. — Much greater tendency to form leaf than stem. One plant with four, and 

 the other with two subdivisions. 12 to 16 inches high, the height greatly due to the 

 length of the leaves. Not a single node clear of the sheath of the one below it ; thus 

 essentially different from the barleys, which have great tendency to form nodes and stem. 

 Fifth pipette-ful of the ammonia-solution added. 



August 10. — Green and nourishing. 



August 24. — Plants 17 to 20 inches high ; ten to twelve leaves on each ; upper ones 

 long, broad, and green ; lower ones dried up. But little tendency to form stem ; leaves 

 larger than on plants in the field ; some 12 inches long and \ inch wide ; no nodes clear ; 

 the leaves spring out so close together as to appear almost opposite. Five stems from 

 the two seeds. 



October 2. — Plants taken up : — 



One seed has given three strong and one small stem ; another one stem ; the third 

 did not grow. Leaves very numerous and close together, giving several thicknesses of 

 sheath around the stem, and hiding all the nodes ; lower leaves dried up ; upper leaves 

 and central axis of growth green. Condition nearly stationary for the last two or three 

 weeks. Average height of plants about 18 inches. 



tSoil quite moist throughout ; also soft, and spongy, rather more so than the pumice 

 soils ; a little water remained in the plate below the pot. 



Roots much, but very irregularly distributed — a large bunch around the base of the 

 stem ; small, long, isolated roots extended to the bottom and up the sides of the pot ; 

 quite a mass of ramified roots over the bottom, and somewhat up the sides of the pot ; 

 and a greater mass in the dish under the pot, forming a circular web the size of the 

 bottom of the pot. A crack in the bottom of the pot was penetrated with roots through- 

 out, showing, perhaps, that more openings than the one hole at the bottom might be 

 advantageous. For representation of the root-development, see Plate XV. fig. 14. 



Preparation and analysis as described at pp. 543, 544. 



No. 7. — Wheat (1857); three seeds ; prepared pumice ; with nitrogenous manure. 



June 9. — Three plants up, 3 to 4 inches high ; each with three leaves completely 

 formed, of which the tips are slightly yellower than those of Nos. 1 and 6, but no appear- 

 ance of diseased condition in any of the wheats. 



June 10. — A pipette-ful of the ammonia -solution ( = -00578 gramme N.) added to 

 the soil. 



June 15. — Plants 5 to 6 inches high, with four leaves each; the tips of the lower 



4 f2 



