A Study of the Vascular System in certain Orders 
of the Ranales. 
BY 
W. C. WORSDELL, F.L.S. 
With Plates XXXII and XXXIII, and four Figures in the Text. 
I 
HE general arrangement of the vascular system in the vegetative 
JL organs, viz. the stems and leaves, of a plant is obviously directly 
correlated with, and the result of, the habit of the plant. Now, according 
to their habit, plants may be grouped into two main series : — 
(1) Grandifoliate plants, in which the stem plays a very subsidiary 
role, the length of its internodes being reduced to a minimum ; the leaves, 
therefore, closely succeed each other, possess wide sheathing bases, and are 
the dominant organs of the plant, e. g. Palms, Water Lilies. 
(2) Parvifoliate plants, in which the stem is the dominant organ of the 
plant, possessing elongated internodes, and bearing comparatively small 
leaves with non-sheathing bases, e. g. Elm, Wall-flower. 
In the former group, the vascular structure of the stem will be 
dominated by and similar to that of the leaf, in which the bundles will tend 
to be scattered throughout the ground-tissue ; in the latter group the 
vascular structure of the stem will be much more independent of, and more 
unlike, that of the leaf, in which the bundles will tend to be arranged 
in an arc. 
Taking the vegetable kingdom as a whole, I regard the grandifoliate 
habit as the primitive one, for the simple reason that I consider the 
bryophytic sporogonitim as the prototype and ancestor of all plants ; 
in this structure the vegetatively- modi fled terminal capsule was the 
primaeval leaf, dominating, as regards size and general development, the 
stem (seta) immediately below it. Out of this developed the subsequent 
leafy plant, by a process of sympodial and lateral branching of phytons 
(‘ Stengelglieder ’), precisely as occurs in the embryo and seedling of, 
Annals of Botany, Vol. XXII. No. LXXXVIII. October, 1908.I 
