Feb. 14,1923 
Distribution of Pentosans in the Corn Plant 
657 
The third series of plants was harvested on June 23 from a plot on 
one of the university farms. Because of the enormous increase in 
pentosans and dry matter in the plants which were harvested on March 9, 
it was felt that a series of plants should be selected which would represent 
a stage of growth intermediate between the series of February 15 and 
March 9, series 4. These plants were about 2 to 2% feet high and were 
just putting out their anchor roots. On analysis, however, it was found 
that they were almost as far advanced as the series of March 9 and did 
not fit into the gap between the second and fourth series as well as 
could be desired. 
On March 9, the fourth series of plants was harvested. These plants 
were about 3 feet high. All of the plants of the second, third and fourth 
series were divided into tops and roots. 
The plants representing the next stage of growth were selected on 
March 26. They were about 5 to 6 feet high and were in the tassel 
stage. The plants were divided into roots, leaves, and stalks. 
The sixth series of plants was harvested on April 12. These plants 
were in the silk stage and of about the same height as those of the 
preceding series. 
On May 18 the plants of the seventh series were harvested. These 
plants were about 6 feet high and had produced ears which were in the 
milk stage. 
The last series was selected on June 1. These plants were from 6.5 
to 7.5 feet high, and the kernels were in the dent stage. The plants of 
the last three series were separated into roots, leaves, stalks, husks, 
cobs, and silk. In the last series the kernels were analysed separately 
from the cobs. 
All the samples were thoroughly washed, dried, and weighed. A sub¬ 
sample of the material was ground to a fine powder and dried over¬ 
night at 105° C. in an electric oven. Duplicate samples of 1 gm. each 
were then taken, and a pentosan determination was made as described 
in the Krober method (<?). With these methods of sampling, grinding, 
and drying, duplicate determinations, checking to within 5 mgm. of 
phloroglucid were easily obtained. If a difference greater than 5 mgm. 
between duplicates was found, the determination was repeated. The 
results of this series of experiments are given in Table I. 
Table I.— Pentosan content of the different parts of the corn plant at various stages 
of growth 
[Calculated on the basis of 100 plants.] 
