32 ee SSL ON AND J. K. Witson 
TABLE 3. Totat Orcantc Marrer anp NitrroGeN PRESENT IN SOLUTIONS IN WHI 
Maize Pirants Hap GRowN 
iKindrofaplanti csc ee sts so eer ieee Maize Maize Maize Ma 
Serialinio decree eee oe Ie een aay 1 2 3 
Date of setting plant in flask.............. May 1 May 1 May 1 May 
Date of removing plant from flask.........| June 23 June 23 | June 23 June 
Growing period (days)...............-.-- 53 53 53 53 
Dry matter in plant (milligrams).......... 17, 266.4 | 23,076.4 | 24,058.5 | 20,448. 
Nitrogen in plant (milligrams) .. Sear ate 307.1 327.4 400.0 365. 
Volume of solution at harvest (cubic. centi- 
TNGGELS) eee ee eee eee 5,875.0 | 4,155.0 | 3,855.0 | 4,870. 
Conditiontotssolutioneee eee ee Sterile Sterile Sterile Steri 
Total organic matter in solution at harvest 
(milliorams) poser eee eee 466 .6 353.1 476.1 535. 
Nitrogen in solution at harvest in form of 
IN@3aGmillagrams) pays ee nee eee 0.0 0.0 0.0 0. 
INIEea(mullaorams)sseeee eerie 0.0 0.0 0.0 - 0. 
Organic matter (milligrams) ............. 1Lo2/ 1.0 1S: 1. 
Ratio of organic matter in solution to dry 
Matter Nap lan tar cesta ers area 1:37.0 1:65.3 1:50.5 1:38. 
Organic nitrogen in deposit (milligrams) .... 0.0 0.4 0.8 0 
Nitrogen in organic matter in solution (per | 
CONE) Es ween ae re tee er eee ae 0.35 0.27 0.27 0. 
The plants used in this experiment made a rather rapid growth, t 
conditions in the greenhouse during May and June being very favoral 
for the growth of maize. Not only had all of the nitrate and ammor 
nitrogen disappeared from the solution, but the organic nitrogen h 
been reduced to a very small quantity, being, in fact, lower than in a 
of the other experiments of this kind. It was rather surprising under t 
circumstances to find so much total organic matter in the solution. E 
dently but a small proportion of the organic matter present was of 
nitrogenous character, as the percentage of nitrogen in the organic mat 
in solution is only about 0.3. Probably there was much carbohydr: 
material present. Knudson’s (1920) investigations led him to conclu 
that reducing sugars are excreted by plant roots. Calculating the nitr 
enous organic matter at 6.25 times the nitrogen present, such mate! 
would constitute only about one-fifth of the total organic matter. It 
altogether likely that the proportion of nitrogen in the organic mat 
varies at different stages in the growth of the plant. 
The ratio of the organic matter in the solution to the dry matter in 1 
plant is surprisingly high. This varied from one part in the solution 
