THE SOURCES OF THE NITROGEN OF VEGETATION, ETC. 571 



leaves, (c) green; 2^ inches high, and still growing, (d), (e), and (f) about 25 inches 

 high to rachis ; each with four or five nodes ; rachis 1^ inch long, with three or four 

 joints barren, and nine or ten with glumes, pales, and some green seeds. 



The Root-development of these Barley plants was very extraordinary. Plant No. 1 

 has about ten roots coming from the first node or point of separation, extending deep 

 into the soil, and some even through the bottom of the pot ; roots also come out from 

 the next joint above, on each of the separate stems, but these do not reach the soil. 

 Plant No. 2, from the first joint, whence spring the six stems, throws out more than a 

 dozen small roots, five of which reach the soil and ramify in it, some of the ramifications 

 going down into the pan. The roots starting within the soil not so much matted near 

 the base of the stem as those of the Wheat ; a good many go down and ramify amongst 

 the flints, or go through into the pan ; they are finer, and not so much blunted and 

 divaricated as the Wheat roots. For illustration of the curious root-development of 

 the barley plant, see Plates XV. fig. 16. 



Soil dry, loose, and porous. 



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



No. 11. — Oats (1858); four seeds; prepared soil; with nitrogenous manure. 



(See Plate XV. fig. 12.) 



April 27. — Seeds set, and pot placed over sulphuric acid, and covered with a glass 

 shade. 



May 7. — The pot removed to its place on the stand. 



May 20. — Three plants up ; 4 to 4^ inches high ; two leaves each ; green and healthy. 



May 22. — A pipette-ful of the sulphate-of-ammonia solution added ( = 0004 grm. N.). 



May 29. — Three plants; 5 to 7 inches high; four or five leaves each; two lowest 

 dead, three uppermost green and growing. These plants have increased the most of 

 any since the addition of ammonia. A pipette-ful of the phosphate-solution added. 



June 7. — Second pipette-ful of the sulphate-of-ammonia solution added ; also a 

 pipette-ful of the phosphate-solution. 



June 19. — Three plants; 10 to 14 inches high; six leaves each; apparently somewhat 

 injured by hot sun the last few days. 



June 21. — Third pipette-ful of the sulphate-of-ammonia solution added. 



June 26. — Fourth pipette-ful of the sulphate-of-ammonia solution added. Three 

 plants, 12 to 14 inches high. No. 1, head developed and obviously seeds forming; one 

 shoot 1 inch, and one 4 inches long from the base. No. 2, head forming; two shoots 

 from the base 4 to 5 inches long. No. 3, much like No. 2. Growth of main stems 

 apparently checked and that of shoots increased by some recent hot weather ; in all, six 

 shoots ; green, healthy, and promising further growth. 



July 3. — Fifth pipette-ful of the sulphate-of-ammonia solution, also a pipette-ful of 

 the phosphate-solution added. 



July 12. — Sixth pipette-ful of the sulphate-of-ammonia solution added. 



