[Vor. 5 
266 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
with due allowance in the final computations for the difference 
in concentration of sample. 
The numerical values of the resulting sugar determinations 
are not presented, for the reason that they show quite con- 
vincingly that the carbohydrate enzymes were not inactivated 
by heating to 90° C. The maltase values, for example, showed 
a content of that sugar which ranged from 14 to 41 per cent 
of the fresh weight of the bulbs. The findings for sucrose 
showed no such disproportionate values, neither did they af- 
ford any data bearing on optimum conditions of temperature 
or length of etherization. The only point of value that ap- 
peared was the fact that the sugar in the bulbs was not 
present to any extent in the form of glucose, but probably all 
as maltose. 'The very great sugar formation must be aseribed 
to a eontinued action of the carbohydrases following the heat- 
ing to 90? C. until the time of analysis. This period, which 
involved the time necessary for completing one of the series 
and the subsequent extraction process, was of considerable 
extent. 
It would appear from these results that the accurate de- 
termination of sugar values or analyses of similar nature 
from solutions thus obtained are not practicable, since a tem- 
perature sufficiently great to inactivate the enzymes present 
would, in the time necessary for its application, undoubtedly 
affect other hydrolytic changes in the presence of organic 
acids which would also introduce a large factor of error. Ap- 
parently the only satisfactory means of dealing with plant 
extracts for analytic purposes is that of alcohol extraction in 
vacuo similar to that described by Davis and Daish (713, 716). 
In the absence of any definite conclusions from these prelim- 
inary trials, it was decided to use the mean conditions of tem- 
perature and time of etherization in the experiments in which 
the extracted enzymes were to be tested. Accordingly the 
temperature used was 30? C. and the exposure to ether 24 
hours. The experiment was divided into two sections; in the 
first the material was extracted immediately at the close of 
the etherization period and in the second it was aired for 18 
hours after etherization and then extracted. 
