4 
pericambium is also different; it is largest in Uvularia. Inside 
the pericambium we see the fibro-vascular bundles in a number 
of about twenty in Oakesia, but only about ten in Uvularia. 
The groups of phloém are relatively larger in Uvularia and the 
xylem shows a stronger development in regard to thickness 
than in Oakesia. As regards the stem overground, we shall also 
here be able to find a few characters. It is solid in Oakesia, but 
hollow in Uvularia. The cells of epidermis do not show any dif- 
ference; their exterior walls are rather thick in both, with a dis- 
tinct cuticle. A quite strong sheath of mechanical tissue forms 
a ring around the fibro-vascular bundles, separated from the 
epidermis in Oakesia by only one stratum of bark-cells, while in 
Uvularia there are two distinct strata between the epidermis and 
the mechanical tissue. This last consists of about five layers in 
Oakesta and but two in Uvularia. 
On turning to the structure of the leaves, the epidermis shows 
the following differences: The cells are relatively much larger in 
Uvularia on both faces, and if we consider simply the inferior 
face, where the stomata are present, the walls of the cells show a 
more distinct undulation in Uvularia than in Oakesia. The 
superior face is perfectly destitute of stomata in both plants. A 
transverse section of the leaves shows also that the cells surround- 
ing the stomata are much broader in Uvularia (Plate CXI, 
Fig. 5). But otherwise in regard to the interior structure of 
the leaf, there was not to be observed any essential difference. 
Figs. 9 and 10, Plate CXII, illustrate a transverse section of the 
midrib, and we see here in both plants that the cells of the epi- 
dermis show rather thick walls with a distinct cuticle, and we 
find inside an almost collenchymatous tissue of about two strata 
(Fig. 11). The fibro-vascular bundles are relatively larger in 
Oakesia, and are not surrounded by any mechanical tissue neither 
in this nor in Uvularia. 
The anatomical characters of these two plants are then: 
THE Root. 
The cell walls of endodermis are thickened in Uvu/laria. 
The cell walls of endodermis are thin in Oakesza. 
About ten fibro-vascular bundles in Uvu/aria. 
About twenty fibro-vascular bundles in Oakesia, 
