40 
T. TADOKORO. 
parenchyma, phloem-parenchyma, cambium and epidermis were stained light 
brown to violet. 
The yellowish red color with safranin was observed on the cell layers 
mentioned above. 
In the beginning of the last period of the retting, the middle lamella of 
fibers showed almost no reaction of pectin compounds, but the cell-walls of 
the cortical parenchyma, phoem-parenchyma, cambium and epidermis still 
showed a faint but distinct color and in the end of this period, the color was 
shown only on the inner thickening layer of fibers. 
3. Protein. With Millon’s reagent, only the fiber lumen was stained 
brick red, the other cortical parenchyma, cambium and epidermis as well as 
the xylem portion being stained very faintly brown. 
4. Lignin. The red color produced on the use of pliloroglucin and 
hydrochloric acid is a characteristic test for lignin. On the cross section, the 
reaction was observed only in the xylem portion and showed no change even 
at the end of the retting. 
5. Tannin. When potassium bichromate was applied on the cross sec- 
tion, we observed the reddish brown color in the contents of the epidermal 
cells and this color almost disappeared at the end of the middle period. 
This phenomenon must be due to the effusion of the tannin from the cells,, 
accompanying the destruction of the inner walls, as the retting proceeds. 
6. Glucose. The quantity of cuprous oxide formed by Fehling’s 
solution on glucose was found to be very little, the greater part of the glucose 
present being dissolved during the retting. 
7. Fat. wax and cutin. For the examination of these ingredients, we 
used three reagents, i. e., sudan III, osmic acid and alcanna tincture. The- 
cuticle, cortical parenchyma, and fiber lumen gave the characteristic reactions 
with sudan III. On the other layer we could not observe any reaction. The- 
same results were obtained with two other reagents. From what we observed, 
we can assume that the cuticle contains cutin, the cortical parenchyma, some 
minute fatty globules, the pith, many fatty or wax-like globules and the fiber 
lumen, fatty substances besides protein. 
Of these substances, we observed further that some of the cutin which is- 
