820 Steward.—Amyloclastic Secretory Capacities of the 
TABLE VIII. 
Secretion of Amylase by the Aleurone Layer (Chilian 
Barley). 
Cultures of isolated aleurone layer on 5 % gelatine subs. Seeds 48 hours absolute alcohol, 
48 hours water (aerated). 
Exp. 
No. of objects 
on culture 
medium. 
Culture 
period. 
Amylase per 20 objects {equi¬ 
valent to mg. of Cu) in :— 
Medium. Objects. Total. 
Augmentation 
of amylase. 
1. 
5 aleurone layers 
4 days 
2222 396 
2618 
J 943 
2. 
99 9 ) 
6 „ 
2172 198 
2370 
1675 
3 - 
99 99 
7 „ 
1428 634 
2062 
1387 
Amylase initially present in 
20 aleurone layers . , 
• 675 
The augmentation of amylase observed in these and similarly conducted 
experiments depends principally on the substitution of absolute alcohol for 
CuS 0 4 in the sterilization of the seeds, and also on the employment of 
a semi-solid medium which affords the fragments adequate mechanical 
support and provides for their aeration. 
The examples given afford sufficient justification for regarding the 
aleurone layer as a glandular tissue, one of the functions of which is the 
secretion of an amylolytic enzyme, and they further furnish evidence that 
the amylolytic capacity of the aleurone layer, as suggested by Brown and 
Escombe ( 1 . c.), is greatly superior to that of the embryo. 
In order to show definitely that passage of amylolytic enzyme from 
the objects cultivated (embryos and aleurone layers) under the conditions 
described actually represents a secretory act, and not a mere passive strain¬ 
ing out of enzyme pre-existent in the tissues of the embryo and aleurone 
layer, the following experiments were instituted :— 
Embryos and dorsal aleurone layers were removed from steeped seeds 
and anaesthetized by immersion for forty-eight hours, at laboratory tempera¬ 
ture, in a saturated aqueous solution of either chloroform or nitrobenzene 
contained in closed vessels. They were then cultivated on 0-55 % asparagin- 
mineral salt solution for seven days under the usual conditions. Examina¬ 
tion of the culture media at the termination of the experiments afforded the 
following data:— 
TABLE IX. 
Culture of Anaesthetized Embryos and Aleurone Layers. 
Seeds (African barley) 24 hours 10 % CuS 0 4 , 24 hours water. 
Exp. Objects. 
Anaesthetic 
reagent. 
Digestion 
period. 
Amylase in culture 
medium per 20 
objects. 
1. 40 embryos 
Chloroform 
20 hours 
2 mg. 
2. ,, 
Nitrobenzene 
1 hour 
4 » 
3. 20 dorsal aleurone layers 
Chloroform 
4 2 » 
4 * » » >> 
Nitrobenzene 
130 „ 
