7 
On the Fruits and Seeds of Rhamnus. 
contents cracked and dissolved like the substance contained 
in the cells of the outer pericarp, leaving the cell cavities 
empty and allowing the shape of the cells to be more clearly 
seen (Figs. 8 and 9). On treating dry sections with glycerine, 
the yellow substance again dissolved, but more slowly than in 
water (Fig. 8). This yellow substance was treated with alco- 
hol, chloroform and ether, and acted in the same way as the 
yellow substance in the parenchyma cells of the outer pericarp. 
Transverse sections were then cut of this inner husk, and the 
cells appeared rectangular, the cell-wall being slightly thick- 
ened on the exterior surface (Fig. 10). 
As regards the rest of the endocarp, thin transverse 
sections were cut, and were found to consist of a number of 
rows of hard sclerenchymatous cells, of which the lumina 
were nearly obliterated, having a very distinct middle lamella 
between the cells, and with a large number of pits radiating 
from the lumina to the middle lamella, corresponding to pits 
radiating from the lumina of contingent cells (Fig. 7). 
Thin transverse sections of the testa were then cut, and it 
was found to consist of a single row of sclerenchymatous cells, 
with a number of pits radiating from the centre of each 
lumen, the cell-cavity containing a greyish substance which 
diffused out of the cell on adding water to the section. The 
middle lamella of the cell-wall was very well marked (Figs. 
11 and 12). 
Thin tangential sections of the endosperm were cut, the 
tissue was found to consist of thin-walled parenchyma, the 
cells containing protoplasm and various other bodies. On 
adding water to the sections oily drops separated out in the 
cells, and exuded at the sides of the sections ; the water was 
then removed and alcohol added, the fatty drops disappeared 
(Fig. 14). Fresh sections were cut and placed dry in alcohol 
and examined in glycerine, the fat had dissolved and a number 
of small grains closely packed were left in the cells. Sections 
which had been treated with alcohol as before were examined 
and water added while under the microscope, and these grains 
dissolved after swelling up. Thus* the endosperm contained 
