Embryo and Aleurone Layer of H ’or deuni. 11 55 
A number of cultures of these objects on 0*55 % asparagin-mineral salt 
medium were prepared in advance, and when ready, after ascertaining that 
they were perfectly sterile, the objects were removed, and the amylase- 
containing medium was withdrawn by means of previously sterilized pipettes 
which were filled as completely as possible and at once sealed off. 
Thus conserved out of free contact with air and protected from the 
light, the enzyme retains its primitive activity for a considerable time. 
Endosperms and inner endosperms, at the termination of the culture 
period on moist calcium sulphate, were first desiccated at 30° C. for twenty- 
four hours, and were then transferred to an ordinary desiccator containing 
H 2 S 0 4 as desiccating agent. 
Determinations of starch-liquefying and saccharifying power of embryo 
and aleurone-layer secretions, and of aqueous extracts of endosperms and inner 
endosperms after cultivation on moist calcium sulphate . 
After a number of preliminary trials of methods of Lintner Sollied 1 
and Poliak, 2 the latter method as modified by Chraszcz 3 was adopted 
throughout the course of these experiments. 
The modification introduced by Chraszcz merely consists in the 
employment of potato in place of arrow-root starch, and substituting other 
temperatures for that indicated by Poliak, viz. 37-6° C. 
Briefly described the details of this method are as follows:— 
Into each of a series of test tubes of uniform size and diameter 10 c.c. 
of a 4 % potato-starch suspension are pipetted, and the tubes and their 
contents are then rapidly placed in a boiling water-bath and their contents 
rapidly gelatinized at a temperature of 65° C. They are then cooled to 
about 6o° C. and transferred to a thermostat the temperature of which is 
regulated at 55 0 C. When the contents of the tubes have acquired this 
temperature a definite but gradually increasing volume of the amylase- 
containing solution to be investigated is added successively to each tube. 
Immediately after the addition of the enzyme solution the tube is 
closed with a rubber cork ; it is then inverted and thoroughly shaken 
to ensure thorough mixing of its contents, and at once returned to the bath. 
Each succeeding tube is similarly manipulated, and after the lapse of 
a chosen time interval, of the same duration for each tube, they are 
successively removed and at once examined as follows:— 
Two to three drops of strong alkali (NaOH) solution are delivered 
from a pipette directly into the digestion liquid, and the manner in which 
they descend through the liquid is carefully noted. If the drops, during 
their descent, retain their spherical form, complete liquefaction has not taken 
place ; if, on the other hand, the drops tend to lose their sphericity and 
1 Zeitschr. f. das gesamte Brauwesen, xxxvi, 1903, p. 329. 
2 Wochenschr. f. Brauerei, xx, 1903, p. 595. 
3 Pierozek, Wochenschr. f. Brauerei, xxvii, 16, 1910, p. 186. 
