3 io 
Ishikawa .—Studies on the Embryo Sac 
Reagent . 
a-naphthol + H 2 S 0 4 
Sudan III 
Osmic acid 
Millon’s reagent 
Eosin 
FeCl 2 
HN 0 3 
NaOH after HN 0 3 
Iodine 
Alcohol 
Ether 
Chromatic substance of the Chromatic substance 
first kind accumulated in of the second 
the chalazal region. kind. 
black 
black 
yellow 
brownish yellow 
insoluble 
soluble 
black 
black 
slightly stainable 
black 
soluble 
Judging from the results tabulated above, the substance of the first kind 
in question must be some ultimate substance which does not share in the 
nutritive process, while the second kind of the substance under discussion 
is really a solution of tannin without question. 
Starch grains in micellar tissue. Iodine solution was employed for 
detecting starch grains both in fixed and fresh 
materials. In the tetrad stage of the mother-cell, 
starch grains accumulate in the nucellar tissue, 
especially densely surrounding the gametophyte 
as well as along the future passage of the pollen- 
tube, where they are found in large granules; 
perhaps some of them become glucose in due 
time, which serves to attract the pollen-tube. The 
grains are also deposited in the chalazal tissue 
neighbouring the terminal portion of the con¬ 
ducting passage. No further change in the 
distribution takes place up to the time of embryo 
formation (Text-fig. XIV), when they gradually 
disappear. Starch grains are totally absent in 
the inner integument, while they accumulate 
more or less in the basal part of the outer 
integument, and as the embryo begins to de- 
seltionoVoTOirs'h^rng'dfetri- velop they spread over the latter. 
bution of starch grains by means As j s 0 ften the case in many plants, the ovule 
of Oenothera has an inner integument, whose 
internal cell-wall facing the nucellus is already 
fully cuticularized in the mother-cell stage of the gametophyte, as demon¬ 
strated with Sudan III. Consequently in the growing ovular tissue, 
nutritive communication of the nucellus with the raphae is restricted only 
to the chalazal portion, where the chromatic substance in question makes an 
early appearance and forms so-called hypostase of Van Tieghem. 
Thus, the case would be very easily explained if we assumed the 
chalazal chromatic substance as a certain nutritive substance which is 
