SOME STUDIES ON THE GERMINATION OF THE SEED OF ORYZA SATIVA. 145 
eyanine, dahlia, light green F.S., and methyl green dissolved in a weak 
alcohol do not enter, while alcohol easily does and destroys the vitality of 
the seed. 
From these facts, we may safely assume that the cutinized layer 
which is derived from the inner integument is the seat of the septum which 
excludes the passage of the chemical compounds selectively. 
III. Role of Oxygen in Germination. 
It is shown by Crocker (1914) on Alisma and by Taxanasut (1905) on 
Oryza that the seed of these plants can be germinated in the absence of 
air. The latter author placed the sterilized unhulled grains in a vessel 
which was flled with thoroughly boiled water and sealed up by means of a 
layer of mercury.. After five days germination was observed, and during 36 
days out of 2.3966 gr. of initial weight of grains, 0.4354 gr. of starch was 
lost by intermolecular respiration. He found bacterial infection in spite of 
sterilization performed by a one-per-mille solution of corrosive sublimate for 
one‘ hour and half. It is uncertain if this short treatment is effective on the 
unhulled grain, for it has been observed that the steeping of the unhulled 
grains in an aqueous solution of potassium permanganate for more than 24 
hours has no effect inside the hulls, whereas hulled grains are totally destroy- 
ed by the same solution within six hours. Furthermore, a trace of air 
might be inclosed inside the hulls, so it seems better to use the hulled grains 
for the experiment. 
By several experiments, using hydrogen gas and a solution of potassium 
pyrogallate, the writer verified the statements of previous investigators, that 
the rice grain needs only extremely low oxygen pressure for the germination. 
The soaked grains are able to bring the embryos to germinate by inter- 
molecular respiration in an atmosphere of hydrogen gas, or in air from which 
the oxgen has been removed by potassium pyrogallate. In addition, it was 
observed that under the anaerobic condition, the development of the plumule 
is possible, but that of the radicle is entirely suppressed. It is peculiar to 
Oryza that the plumule appears first in germination, contrary to the majority 
of Graminineae, in which the development of the radicle precedes that of the 
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