COMPOSITION IN SUCCESSIVE STAGES. 211 
(33°|,,) is found in the 4th; in the upper leaves, (38°|,,) in 
the 2d period. 
The apparent diminution in amount of fiber is due in 
all cases to increased production of other ingredients. 
2. Fat and Waz are least abundant in the stem. Their 
proportion increases, in general, in the upper parts of the 
‘stem, as well as in the later stages of its growth. The 
range is from 0.2°|, to 3°|,. In the ear the proportion in- 
creases from 2°|, to 3.7°|,. In the leaves the quantity is 
much larger and is mostly wax. The smallest proportion 
is 4.8°|,,.which is found in the upper leaves, when the 
plant is tipe. The largest proportion, (10°|,,) exists in 
the lower leaves, at the time of blossom. The relative 
quantities found in the leaves undergo considerable varia- 
tion from one stage of growth to another. 
3. Non-nitrogenous matters, other than fiber,—starch, 
sugar, etc.,*—undergo great and irregular variation. In 
the stem the largest percentage, (57°|,,) is found in the 
young lower joints; the smallest, (43°|,,) in ripe upper 
straw. Only in the ear occurs a regular increase, viz., 
from 54 to 63°|,. 
4, The Albuminoids,}-in Arendt’s investigation, exhibit 
a somewhat different relation to the vegetable substance, 
from what was observed by Bretschneider, as seen from 
the subjoined comparison of the percentages found at-the 
different periods. 
Periods. 
I. Il. Ifl. IV. Vv. 
Avendt.........006 20.93 1165 10.86 13.67 14.30 
Bretschueider .... .22.73 17.67 17.61 15.39 
These differences may be variously accounted for. They 
are due, in part, to the fact that Arendt analyzed only 
large and perfect plants. Bretschneider, on the other 
* What remains after deducting fat and wax, albuminoids, fiber, and ash, 
from the dry substance, is here included. 
+ Calculated by multiplying the percentage of nitrogen by 6.33. 
