268 
SVBDELIUS: LIFE-HISTORY OF 
a pedicellis soluti in aquae superficie natantes.” Zollinger, 
however, was of the peculiar opinion—which is in strong 
contrast with the real circumstances—that the female 
flowers were drawn down to the male flowers underneath 
the surface by the spiral contraction of the pedicels. 
As no observations have been made upon this plant in its 
living condition or natural habitat, and as it is only from 
analogy that the inferences are drawn by which we have 
the notices on its pollination which occur in botanical 
literature, I shall give an account of the life-history as 
detailed as is possible with my material, the rather as I 
think that i L , will appear that the pollination does not agree 
in detail with that of Vallisneria, as perhaps one might 
think from the statement of Ascherson and Giirke (5). 
In the Ceylon flora Enalus acoroi des only occurs in a rather 
limited district in the north, viz., around the islands in the 
Gnlf of Mannar, e.g^ at Jaffna and at Paumben on the Indian 
island of Ramisseram, where I first had the opportunity 
to investigate thiB plant. There it occurs around the shores 
in the shallow water to a great extent, sometimes in large 
masses forming a kind of submarine meadows on a depth at 
moBt of about a meter and a half at flood-tide. It occurs 
only on soft muddy bottom, where the shoots grow deeply 
down in the silt. 
In regard to general organization and vegetative structure 
this plant is already known in its principal features, so that 
I may refer to the papers of Griffith (12), Ascherson (2-5), 
P. Magnus (4), and Sauvageau (27, 28). 
The Root.— From the rootstock emerge few but rather 
large roots of uniform character. In their anatomy they show 
normal root-structure. The epidermis with very few root- 
hairs is in function only at an early stage. The outermost 
layer of the cortex is developed as exodermis; the other cells 
of the cortex are arranged in radial layers with intercellular 
spaces. In the external part there arise large air-chambers 
separated by (in a cross section) radial rows of tissue. The 
