138 ISABURO NAGAI: 
appears to lie directly above the aleurone layer, for the lower layer (Pl. IX 
fig. 1-2, n) is resorbed. It is a difficult task to ascertain, whether the cutinized 
layer is derived from the upper cell layer or from the underlying cell layer. 
For this point, the writer is indebted to Dr. Kuwapa, who kindly allowed 
the writer to refer to the slides and the drawings made by him in his 
cytological studies on Oryza. At a very early stage in the development of 
the embryo, both the inner and outer integuments are clearly seen and the 
inner wall of the inner integument, which faces the nucellar epidermis, is 
eutinized. The cutinized layer observed in the matured grain, then, must 
be considered to have been derived from the upper cell layer which must 
be the inner layer of the inner integument; accordingly, the underlying cell 
layer must belong to the nucellus. 
The green colour of the immature grain is due to the presence of many 
cholorophyll bodies in the parenchym of the pericarp, and they are rich in 
starch grains. As maturity advances, the chlorophyll bodies disappear, except 
in the two slender “ chlorophyll cell” layers, and finally the chlorophyll bodies 
are lost even from the latter. The tube cells, which are loosely attached, 
are arranged along the longitudinal axis of the grain, so that the transverse 
section of the grain gives their cross sections (Pl. IX, fig. 1, t). The tissue 
above the tube cells (the pericarp) can be pealed off from the remaining tissue 
(the spermoderm), and the majority of the tube cells remain on the part 
of the spermoderm. 
The following microchemical tests were made with fresh and fixed 
materials. The parenchym of the pericarp gives a reaction of cellulose by 
potassium teriodide (I-KI) with concentrated sulphuric acid. Cupra ammonia 
dissolves them slowly. No lignin reaction is observed either by phloroglucin 
or by a-naphthylamine with a strong solution of hydrochloric acid, except in 
the wall of tracheid of the vascular bundle. According to Nowackı (1870), 
however, the chlorophyll-containing single cell layers of the pericarp and the 
underlying tube cells in wheat grain are lignified. This is not the case 
with rice grain. The cell wall of the chlorophyll layers and the tube cells 
dissolve in a concentrated solution of sulphuric acid, and by an addition of 
I-KI, a deep blue color is produced. j 
A solution of ruthenium-red stains the cell wall of epidermis, 
