656 
Jour nal of Agricultural Research 
voi xxm. No 8 
The question whether the pentosans may serve as reserve substances 
in the plants has been made a subject of study by numerous investiga¬ 
tors. De Chalmot (j), Schone and Tollens (12), and Gotze and Pfeiffer 
(7) have concluded that the pentosans do not act as reserve substances. 
It has been shown that no decrease results in the pentosan content of 
plants during the different stages of development and hence the plant does 
not draw on the pentosans for the support of its life processes. Some 
exceptions appear to this general condition, as in the germination of 
the seeds of Tropaeolum majus (2), and in the decrease of pentosans in 
tree trunks (17) during the growing season. In a recent paper Totting- 
ham, Roberts, and Lepkovsky (19) suggested that xylose-yielding 
substances may act as reserve carbohydrate in the metabolism of the 
apple tree. Miyake (9) determined the quantity of pentosans and 
methyl pentosans in the cotyledon and embryo of the germinated and 
ungerminated seeds of garden beans and soybeans and concluded that 
ordinarily the pentosans do not serve as reserve substances but that when 
the more easily utilizable material is used up the pentosans may function 
as reserve material. Schulze (jj) and Ravenna and Cereser (ji) are 
also of the opinion that in certain instances the pentosans may be used as 
reserve material. 
Although the physiological function of the pentosans is still obscure 
and unsolved, it is doubtful whether their origin is the result merely of 
an accumulation of waste material. It is probable that they have some 
real importance in the formation of wood and in the formation of the 
skeletal structure of the various plants. 
Associated with the pentosans are the methyl pentosans which have 
been found in mosses, algae, cereals, fungi, and in other plant material. 
Borghesani (j) made a study of the relationship between the amounts 
of pentosans and methyl pentosans in different species of soybeans and 
com and found that this ratio was practically constant. However, little 
more than the wide occurrence and seemingly intimate relationship to 
the pentosans is known concerning the methyl pentosans. 
A study of the pentosans and free pentoses in the com plant at the 
various stages of growth seemed highly desirable* and these observations 
are described in this paper together with some data on the fermentation 
of the pentosans of green corn fodder by pure cultures of a number of 
bacteria. 
EXPERIMENTS 
Com of the variety known as Golden Glow was planted in the green¬ 
house on January 15. The first plants were harvested on February 2 
and were about 9 to 12 inches high. The plants were uprooted with the 
utmost care in order to obtain the entire root system and dry outer 
shell of the germinated kernel which is still attadied to the plant at this 
stage of growth. These plants were not separated into tops and roots 
before determining the pentosan content. Some of the plants at the 
same time were harvested without the root system. Upon analysis it 
was found that the tops contained a considerably smaller percentage of 
pentosans than the whole plant. The plants of the succeeding stages 
were consequently divided into tops and roots. 
The second series of plants was harvested on February 15. These 
plants were from 12 to 15 inches high and were just putting out their 
anchor or surface roots. They also still had the outer shell of the kernel 
attached to the root system. 
