1905] DEAN—PROTEOLYTIC ENZYMES 125 
coaguable and non-coaguable nitrogen were determined in the seeds. 
and in the cotyledons of young seedlings. 
About 75%" of beans were soaked in water and the cotyledons 
separated from the skins and embryonic plants. The cotyledons 
after being washed were dried at 60° C. and ground in a hand mill, 
yielding the preparation A. Another part of the same lot of beans 
was planted in the greenhouse and allowed to germinate for seven 
days. At the end of this time the somewhat shrunken cotyledons 
had been pushed above ground, had begun to turn green, and 
were separating to allow the plumules to push out. These cotyle- 
dons were removed from the plants, washed, and dried at 80° C. 
When dry they were ground in the mill, giving preparation B. Por- 
tions of both A and B were rubbed to the finest powder possible in the 
mortar and dried at 100°C. to constant weight. Duplicate portions 
of 1" each of A and B were then weighed into small beakers, 15°° 
of water added, and, after bringing to a boil, 2 drops of 10 per cent. 
acetic acid were stirred in. After allowing the coagulated proteids 
to settle for a moment or two the contents of each beaker were trans- 
ferred to a dry washed filter paper in a funnel held in a Kjeldahl 
digestion flask. The washing of the precipitates and their quantita- 
tive transfer to the filters was effected by the use of six portions of 
5** each of boiling distilled water. After thoroughly draining, the 
filters with the contained precipitates were transferred to Kjeldahl 
flasks; the precipitates and filtrates were then analyzed for nitrogen 
with the following average results: 
Total nitrogen in A =0.04078m = 4.17 per cent. 
Total nitrogen in B=0.03968™ 3.96 per cent. 
Percentage of nitrogen in A as coaguable proteids=9o0.7 per cent. 
Percentage of nitrogen in B as coaguable proteids=61.4 per cent. 
Percentage of nitrogen in A as soluble compounds= 9.3 per cent. 
Pereentage of nitrogen in B as soluble eompounds = 38.6 per cent, 
: It is worth noting that in the germination of the bean the consump- 
ton of nitrogenous foods proceeds at practically the same rate as 
that of the non-nitrogenous materials stored there; as a consequence 
the Percentages of nitrogen in the cotyledons in the various stages of 
Sermination are nearly constant. After the cotyledons have become 
“mptied the percentage of nitrogen changes, since the cell walls of 
