Fossombronia longiseto , A list. 85 
stages of leaf-growth in very young plants. Normally the leaves range 
from 1 to 3J or 4 mm. in length, though it is not unusual to find strong, 
vigorous plants bearing leaves 5 or more mm. in length. 
The leaves are always more or less imbricate and irregularly lobed, 
the apex of each lobe terminating in a relatively small, somewhat elongated 
mucilage-cell. These cells are further characterized by the total absence 
of chlorophyll, and by the presence of a few oil- bodies. Hanstein’s Aniline 
mixture was used as a mucilage test, in each case giving the characteristic 
mucilage reaction — a marked scarlet red. Iodine was also employed, 
producing a bright yellow in the older cells, and a deeper brownish colour 
in the young cells. These mucilage-cells are of the same physiological 
f k 
Fig. 2. A. Portion of leaf-margin showing two mucilage-cells (m) containing scattering oil-bodies (pb.). 
x 560. B. A similar cell attached to an elevated leaf-cell, x 560. C. A glandula hair, x 560. 
significance as the mucilage-hairs that develop upon the surface of the 
stem, and along with these are of undoubted value to the plant in aiding it 
to resist the effect of prolonged drought. Early in the autumn of 1903, 
before the advent of the rainy season, a quantity of the material in a 
thoroughly dry condition was brought into the laboratory, and a portion of 
it was moistened. In the course of twenty-four hours the apical ends of 
the more vigorous plants had revived, and were green to a length of a 
millimetre or more. Such a sudden revival of so much of each plant 
suggested the idea that one might possibly find antheridia and archegonia 
already fairly well developed at the inception of the dry season. Con- 
siderable material was examined shortly after being revived, and in many 
cases nearly mature organs were found that could only have developed 
before the plants were dried. 
