BOTANY OF THE CEYLON PATANAS. 445 
a second row is pronounced are furnished by the leaves of 
Dodonea viscosa, Heptapleurum stellatum (PI. 11. fig. 8), Rubus 
moluccanus, and Ehododendron arboreum—the last has even a 
third row of palisade-cells. 
In some cases the mesophyll is more or less irregularly 
palisade throughout, the cells usually decreasing somewhat in 
length from the upper to the lower surface. The leaves of 
Crotalaria albida, Flacourtia Ramontehi, Polygala telephioides, 
Psidium Guyava (P1.11. fig. 7), Rhodomyrtus tomentosa, Tephrosia 
tinctoria, and Zornia diphylla show this in varying degrees. 
In order to gauge the palisade nature of the upper mesophyll, 
the length of its average cell should be compared with its 
breadth. This has been done, and the results inserted in 
Column XIII. of the Table. The measurements have been taken 
of the uppermost palisade row where two occur, and of the average 
cell where the palisade ones are somewhat irregular in length 
and breadth. The average figure for the column is 5, i. e., the 
length of the palisade-cell is on the average five times its breadth. 
The most marked palisade-layer is seen in Glochidion zeylanicum, 
where the length of the individual cell is eleven times its width. 
Haberlandt * remarks that palisade-cells vary from being 
scarcely longer than broad to having a length 10-12 times their 
breadth. 
From the figures in Columns XI. and XII. the relative 
proportions of palisade and spongy tissues can be calculated. 
On an average the spongy is one and a half times as deep as the 
palisade ; only those plants, fifty-two in all, which have these 
layers fairly well marked off one from another are taken into 
account. Blumea crinita has the largest proportion of spongy 
tissue, viz., six times the depth of the palisade. 
As regards the development of intercellular space in the 
spongy tissue or in the mesophyll as a whole, about 40 per cent. 
have very little, 7. e. the mesophyll is compact. 
V. Tur Anaromicat Cuaracters oF THE Lear or THE “ WET” 
AND “ Dry” Parana PLANTS COMPARED. 
Having briefly summarized the anatomical characters of the 
Jeaves as a whole, we now proceed to compare the plants of the 
“wet” patanas with those of the “dry” patanas. As previously 
mentioned, twenty-eight belong to the “ wet,” thirty-three to the 
* Haberlandt, Phys. Pflanz.-Anat. (1896) p. 228. 
