PLATE 14 
1. —Longitudinal section of a stem of Riscnus communis , showing copious prolifera¬ 
tions due to a 5 per cent g* ape-sugar solution and restricted to the injected intemode. 
Entire wall covered with granulations in the lower part of the figure. The large nodule 
below the black-paper background developed around the needle entrance. The white 
band behind this at the left and on the lower right side is dead pith. X2. 
2. —Cross section below figure 1. The dead pith (white ring) encircles the inner, 
still living granulations. Injected August 7, 1916, Photographed on August 24. 
X2. 
3. —Cross section of a Ricinus intemode which received 0.2 c. c. of clear lime water 
when young. No evidence of wound-repair tissue, but the pith cavity filled solid 
(save for a black speck in the center) with pith cells as in a very young intemode. The 
white area represents the line along which the outer pith would later have separated 
from the central core. There was much diffuse red stain in the living pith outside of 
the white (dead) area, and this pigment which was also abundant in the intemodes 
injected with sodium bicarbonate stained Camoy’s fluid decidedly red. This red 
stain is perhaps to be accounted for by an excessive movement of sugar into the 
treated intemodes. The normal diameter of the pith cavity of a Ricinus stem of this 
age and shape would be about 17 by 12 mm. Intemode injected on August 8, 1916. 
Photographed on August 24 about 1 inch above the lower node. Only the lower 2.5 
cm. of the lumen (part below the needle entrance) was completely filled with tissue. 
Xi H (nearly). 
