132 BOTANICAL GAZETTE [avcust 
of the emptying cotyledons. The cotyledons of ten-day old seedlings 
contain much more ereptase than those of the three and five-day old 
ones. The ten-day cotyledons were green, shriveled, and probably 
contained no proteids except those of the protoplasm. As a conse- 
quence, the number of cotyledons needed to contain 0.028™ of nitro- 
gen was far larger, the number of cells used much greater, and the 
amount of protoplasm probably far in excess of the amount in the 
digestion with younger cotyledons and ungerminated seeds. It is 
doubtful if there is any increase of ereptase per cell during the process 
of germination; if that is the case, the amount of ereptase per unit of 
protoplasm contained in the seeds and young cotyledons is much 
more clearly indicated by the results obtained with the exhausted 
cotyledons than by those obtained with the storage tissues themselves. 
In many cases it is evident that there is no special quantity of ereptase 
formed in the germinating seeds for the purpose of digesting the 
reserve proteids. The unexpected activity of the root tissue is prob- 
ably connected with some processes, as yet unknown, which occu! 
there and which are associated with the nitrogenous metabolism of 
those organs. VERNON obtained just such a suggestive result with 
the kidneys of several warm blooded animals; it is probable that 
there are Processes occurring in that organ which are now unknown, 
but which involve a rapid nitrogenous metabolism. 
CONCLUSIONS. 
The results of this study have shown that, as was to be expected, 
the Proteids of the seeds of Phaseolus vul garis undergo proteolyss 
during germination as a preliminary to the transportation of the 
nitrogen and its utilization in the formation of new organs. Thet® 
_— three ways in which this process might be carried out: by : 
action of a tryptic enzyme; by the combined action of the protoplas® 
and of an enzyme which is, by itself, incapable of carrying oe 
Whole process; or by the action of the protoplasm alone. The resull 
. a study of the proteolytic enzymes of the resting and germinate 
ean show that there is no enzyme present which is able to diges 
the proteids of the seed. There is present, however, an enzyme : 
the Ai nae: Sroup which is capable of digesting the proteoses result: 
ng trom the partial hydrolysis of the seed proteids. It may © 
