128 BOTANICAL GAZETTE [FEBRUARY 
Whether enzymotic or not, the reducing action on sodium selenite 
is most marked intracellularly in the parenchyma cells of the root 
tip. The primary localization of the deposited selenium in the 
root tip speaks neither for nor against the enzyme nature of the 
reducing power. 
Reduction of sodium selenite may be brought about by purely 
chemical means. Thus Griiss (28) found that lactic acid could 
precipitate selenium from sodium selenite. Lactic acid we have 
found to have no reducing action on sodium selenite of a strength 
of 0.25 per cent, but has some reducing action on a 4 per cent 
solution of sodium selenite, especially on warming. Citric, tar- 
taric, malic, and oxalic acids do not reduce sodium selenite in the 
cold, but do reduce strong solutions of the selenite on boiling with 
a slight excess of the acid. Hydrochloric acid has no reducing 
action on the selenite solution. Citric, tartaric, malic, and oxalic 
acids have a reducing action likewise on ferric salts, converting 
them to the ferrous form. Unsaturated fatty acids such as oleic 
and elaidic also have the power to reduce sodium selenite and 
tellurite to metallic selenium and tellurium on warming the mix- 
tures on the water bath. Dextrose likewise reduces the selenite 
and tellurite on warming. A strong solution of sodium selenite 
mixed with a solution of invert sugars made by warming cane 
sugar with dilute hydrochloric acid was completely reduced in the 
slightly acid mixture on standing 48-72 hours at the room tem 
perature of about 30° C. 
JONES (29) injected selenate into the blood of animals. The 
selenate was reduced to selenite, a small part of which was excreted 
in the urine. The remainder was carried to the spleen and liver, 
where it was reduced by dextrose to selenium. When the dextrose 
was exhausted, fat was called upon. JoNEs suggests that dextrose 
is possibly the means by which all reduction processes in the body 
are brought about. He found that arabinose, glucose, and sugars 
yielding glucose would reduce sodium selenite on heating, while 
levulose could reduce it at 30° C. on long standing. ° 
As regards the reduction of sodium selenite and tellurite by 
wheat roots, it seems probable, since no reducing enzyme could be 
extracted from the crushed plant, although the juice did show reduc- 
