438 MESSRS. J. PARKIN AND H. H. W. PEARSON ON THE 
JIT. Expnanation oF TABLE. 
The eighty plants whose leaves have been examined are 
arranged in alphabetical order. The endemic species are printed 
in italics. The measurements are given in » (7001 mm.). The 
whole thickness of the leaf is not recorded, as this can be 
obtained by adding together that of the mesophyll and of the two 
epidermal layers. The measurements were made from sections 
of the alcoholic material mounted in water and in places where 
the vascular bundles (veins) were absent—such being usually the 
thinnest part of the leaf-lamina. 
Oolumn I. refers to the type of patana on which the plant 
grows. “w” means confined to “ wet” patana, “d” to “ dry,” 
and “wd” common to both. Those of the third group were, with 
two exceptions, collected in one of the regions only—to express 
this the letter denoting the other patana is included in brackets ; 
e.g. w(d) means that the plant is common to both, but the 
material for examination was only obtained from the “ wet” 
patanas. 
Column II. Letters “er” and “ser” refer respectively to the 
erect or semi-erect position of the leaf recorded in the field 
observations *. In the case of plants the leaves of which move 
into a profile position in bright sunlight, the fact is denoted by 
the letters “sm.” 
Columns III. and V. record the average depths of the upper 
and lower epidermal layers, exclusive of the thickness of the 
outer walls respectively. 
Columns IV. and VI. record the average thickness of the outer 
walls of the upper and lower epidermal layers respectively. 
Columns VII. and VIII. give the average number of stomata 
per square millimetre of leaf-area on the upper and lower 
surfaces respectively. When the space in column VII. is left 
blank it means that stomata were not observed on the upper 
surface. When “vf’’ occurs, it signifies that only an occasional 
stoma was seen—too few to average out toa square millimetre. 
Column IX. gives the depth of the mesophyll. 
Column X. its differentiation. “dy” stands for dorsiventral, 
“ib” for isobilateral or an approach to this type. “ grad” 
denotes that the palisade (upper mesophyll) is not sharply 
* Pearson, Journ. Linn. Soc., Bot. xxxiv. (1899) pp. 328-331. 
