556 Transactions. 
cells of this tissue. These bodies would appear to be connected with the 
colourless bodies in the fresh specimen, and it is probable that they were 
identical with them. 
Growth takes place as in the lamina by the active division of the outer- 
most layer of cells, which are more densely filled with the brown colouring- 
matter than the other cells of the cortical tissue. These cells divide only 
from their inner side, and so give rise by continued division to the radial 
rows of the cortex. The cells of the cortex again gradually pass over into 
the next layer by continued growth, and so each tissue increases in size 
from the one directly outside it. 
On experimenting with a stipe from an adult plant, after Detmer’s 
method (1898, p. 20), to extract the brown colouring-matter from the 
outer layers, it was found that it differed greatly in this respect from portions 
of the frond. The colour of the stipe is always much lighter than that of 
the frond, and the brown colouring-matter is not extracted by boiling 
water or by alcohol, while it is readily extracted from the frond in either 
way, leaving the green chlorophyll in the cells. 
The sti ad a diameter of 6:25 cm., and a traverse section 
here are only two clearly defined tissues present in the lamina, the 
outer cortical or assimilatory, the inner medullary or conducting. 
