94 Green. — On Vegetable Ferments. 
covered with an epithelium, the appearance of whose cells 
certainly suggests a secretory activity resembling that of the 
scutellum of the barley. The outer walls of the cells com- 
posing this epithelium are thicker than those of the similar 
membrane of the latter, and it is difficult to see how the proto- 
plasm contained in them can exert any direct action upon the 
endosperm. This, together with the granular appearance of 
the contents of the cells during the period of absorption, 
certainly points to a secretory activity leading to the excretion 
of an enzyme into the endosperm. The walls of the latter 
become softened so as to be easily cut and are then irregularly 
corroded and broken down. In another Palm ( Livistonia ) 
this disappearance of the cellulose is associated with the 
appearance of sugar, which can be demonstrated in the dis- 
integrating endosperm and in the absorbing cells of the 
haustorium. A little deeper in the tissue of the latter, starch- 
grains make their appearance long before any leaf has been 
developed in the young embryo. The endosperm-cells, when 
extracted with the usual solvents, fail to yield any evidence of 
the presence of an enzyme, nor is there any satisfactory proof 
of the existence of such a body in the epithelium of the 
haustorium, though certain experiments carried out by the 
writer 1 appeared to show that there was a trace of one 
present. These results have not however been confirmed by 
subsequent observers, and up to the present therefore the 
search for a cytohydrolyst in the Palms has not been success- 
ful, though probably only better methods of experiment are 
required to establish its existence. 
We have, however, evidence that the vegetable kingdom 
contains such bodies, and that in probably not exceptional 
cases. 
De Bary in 1886 published particulars of some experi- 
ments on the Pezizas of the Sclerotinia-group in which he 
noticed a behaviour of the hyphae which suggested to him 
the occurrence of an enzyme there. When he cultivated 
these fungi on the pulp of carrots and turnips, he found that 
1 Phil. Trans, vol. 178 B. p. 57, 1887. 
