1170 Stoward.—•A my loc las tic Secretory Capacities of the 
The specificity of the enzyme has been challenged by Griiss, who 
suggests that the manifestation of its activity is merely a function of 
ordinary ‘ diastase \ 
The study of cellulose-dissolving enzymes has been exhaustively 
carried out by Newcombe, 1 and the conclusion is arrived at that barley- 
malt extract contains a specific cytoclastic enzyme. 
Apart from the question of endeavouring to ascertain whether cytase 
really represents a distinct enzyme it appeared desirable to ascertain 
whether, as asserted by Brown and his co-workers, the secretion of a cyto¬ 
clastic enzyme is one of the several functions of the embryo and aleurone 
layer. 
The preparation of sterilized experimental material appeared to afford 
exceptional opportunities of testing the cytoclastic secretory powers of 
these objects over prolonged periods of time and of thus giving them full 
facilities for the display of their presumed cytoclastic functions under 
conditions which absolutely precluded the possible interference of disturbing 
influences, such as micro-organisms, &c. 
After the customary series of orientation experiments the following 
method of experiment was adopted :—Embryos and fragments of aleurone 
layers were prepared from seeds sterilized by steeping them successively 
in alcohol and water under the usual conditions, and placed upon thin 
transverse sections taken from various parts of the endosperms of similarly 
sterilized seeds. 
In each of a series of Petri dishes was placed a triangular glass 
tripod, and on it were laid several microscopical slides and on each of 
the latter three microscopical coverslips were placed ; the dishes were 
finally sterilized by heating to 160° C., and afterwards when sufficiently 
cooled 2-3 drops of 5 % gelatine-mineral salt medium were delivered with 
a sterilized pipette and a single thin endosperm section embedded in each 
little mass of medium. Prior to the setting of the medium either an 
embryo or aleurone-layer fragment was laid on the section with its 
scutellar or inner surface respectively downwards and in close contact 
with the section. Similarly prepared miniature ‘cultures’ containing 
endospermic sections without the superposition of the objects mentioned 
served as controls. A small quantity of sterilized water was then run into 
the dish in order to prevent undue desiccation of the droplet of culture 
medium. 
Under these conditions it was possible to carryout experiments of long 
duration and to examine the section without disarranging its component 
parts, a point of very considerable importance when, as we shall see in 
these experiments, often the cytoplasmic network alone remains. 
The object of these experiments was not to examine the progress of 
1 Ann. Bot., xiii, 1899, p. 79. 
