THE SOURCES OF THE NITROGEN OF VEGETATION, ETC. 567 
July 14.—Seventh pipette-ful of ammonia-solution added. Details of growth from 
the four seeds as follow :-— 
No. 1, one stem only, 8 to 10 inches high; three upper leaves green and vigorous, 
four lower yellow. No. 2, three stems: (a) 3 to 4 inches high, two yellow and two green 
leaves; (6) 4 to 6 inches high, two yellow and two green leaves; (¢) 12 to 14 inches 
high, three yellow and three green leaves. No. 3, three stems: (a) 4 to 6 inches high, 
two yellow and two green leaves; (2) 8 to 10 inches high, two yellow and three green 
leaves; (c) 13 to15 inches high, two yellow and three green leaves. No. 4, four stems, 
8 to 10 inches high, three yellow and three green leaves each. 
The “ yellow” leaves are small ones at the base, developed before ammonia was added, 
and are dead. The ammonia strikingly developes the new shoots, and their leaves are 
much larger. As last year, much more tendency to form leaf than run to stem. The 
height given above includes that of the erect leaves extending above the ascending axis. 
July 19.—Eighth pipette-ful of ammonia-solution added. 
July 29.—Ninth pipette-ful of ammonia-solution added. The following details will 
show how dependent is the development upon the proximity to the mouth of the tube by 
which the ammonia-solution is applied. 
No. | (furthest from the tube), one stem strong and vigorous at the base, and 13 inches 
high. No. 2 (third from the tube), three stems; one 12 to 13 inches high, the others 
smaller. No. 3 (second from the tube), five stems; three 12 to 13 inches high, and two 
new ones | to 2 inches high. No. 4 (nearest the tube), seven stems; four 8 to 13 inches 
high, and three new ones 1 to 3 inches high. 
All upper leaves green and vigorous, most of the lower yellow and dead; some of the 
shoots entirely green. 
August 10.—Tenth pipette-ful of ammonia-solution added. 
August 17.—Eleventh pipette-ful of ammonia-solution added (a new solution, the 
pipette-ful =0-00359 gramme N.). 
Recently, much more disposition to form stem; several plants from 18 to 30 inches 
high ; nodes clear of the sheaths. Comparing with the Wheat without ammonia, which 
also tends more to stem of late, it appears that the amount of growth is due to the supply 
of combined nitrogen, and its character (stemmy) more to the season. 
August 26.—Twelfth pipette-ful of ammonia-solution added. 
September 7.—Thirteenth pipette-ful of ammonia-solution (the last application ; in all, 
0:0508 gramme N.) added. Growth from each seed as under :— 
No. 1 (furthest from the ammonia-solution tube), one stem 23 inches high; twelve 
leaves; two nodes clear; slight indication of heading. 
No. 2 (third from the tube), one main stem growing, and two shoots dead; main stem 
23 inches high; three upper leaves green, six lower ones yellowish; not heading yet. 
No. 3 (second from the tube), three stems; two like “No. 2”; the third 12 to 14 
inches high; little tendency to form stem, but long leaves from the axis. 
No. 4 (nearest the tube, some of the roots washed when the solution, or water, is 
MDCCCLXI. 4 
