THE SOUECES OF THE NITROGEN OP VEGETATION, ETC. 5G7 



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; (b) 4 to 6 inches high, two yellow and two green leaves; (c) 12 to 14 inches 

 high, three yellow and three green leaves. No. 3, three stems : (a) 4 to G inches high, 

 two yellow and two green leaves ; (b) 8 to 10 inches high, two yellow and three green 

 leaves; (c) 13 to 15 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. 1 (furthest from the tube), one stem strong and vigorous at the base, and 13 inches 

 high. No. 2 (third from the tube), three steins; one 12 to 13 inches high, the others 

 smaller. No. 3 (second from the tube), five stems; three 12 to 13 niches high, and two 

 new ones 1 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 (stenimy) more to the season. 



August 2G. — 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 II 



