280 BOTANICAL GAZETTE [APRIL 
SPITZER (15) attributes the oxidizing power of animal tissue 
to the nucleoproteid they contain, the oxidizing power of the nucleo- 
proteid being due to the combined iron they contain. In the 
absence of sufficient oxygen the same nucleoproteid acts as a redu- 
cing agent. BrrTrANnp (16, 1'7) showed that the oxidizing power 
of laccase from Rhus vernicifera is associated with the presence of 
manganese, and that laccase of alfalfa, which is poor in manganese, 
is inactive toward hydroquinone (18). The mixture of a trace 
of manganese salt and alfalfa laccase had strong oxygen-carrying 
power where either constituent alone had very little. Other metals 
such as iron, aluminum, cerium, zinc, copper, calcium, magnesium, 
and potassium did not increase the oxidizing power of laccase. 
BERTRAND showed that manganese salts which are easily hydro- 
lyzable are most efficient oxygen carriers. He considered the active 
oxidase as special combinations of manganese and an acid radical, 
the latter probably of a proteid nature and partaking of the proper 
ties of a ferment. The manganese would be the really active 
element of the oxidase, while the acid radical would give the ferment 
the other properties such as solubility and sensitiveness to heat. 
According to Rey-PAILHADE (19), the reducing ferment which 
he found in plants, and which he has described under the name 
“philothion,” possesses the properties of the acid albuminoid 
radical of the oxidases. 
In connection with BERTRAND’s conception of the action of 
manganese and our study of the oxidation action of wheat roots, 
it is interesting to note that manganese has been found by 
MAUMENE (20) in many plants, among them wheat, as 4 salt of 
an organic acid. PrcHarp (21) and Géssi (22) found manganést 
widespread in plants and animals. On the other hand, Vapamt (23) 
found no manganese in the oxidase of hellebore, but did find 110? 
SartHou (24) found only calcium, iron, and sodium in the oxidase of 
Schinus molle; while De StoECKLIN (25) could not find manganes? 
in the ash of the oxidase from horseradish. Bacx (26) believe 
he has obtained from molds an active oxidase which is entirely 
free from iron or manganese. VAN DER HAAR (27), howers 
doubts the validity of Bacn’s conclusion as regards the absence © 
of manganese. Evter and Botin (28) found that laccase from 
