ANATOMY OF ENHALUS ACOROIDES. 367 
bundles of the bract ; the small median peripheral bundle of the peduncle continuing as 
the median abaxial bundle of the bract. 
The bract-bundles, in common with the leaf, have their median and marginal bundles 
derived from the central vascular system, while the smaller ones arise from the peripheral 
bundles. 
The Pedicel.—The pedicel, though cylindrical, is dorsiventral in structure and 
consists of two external rings of parenchyma-cells (Pl. 36. fig. 17, p), surrounding two 
lacune (Pl. 36. fig. 17, 2) (separated by a trabecula, £), which run the whole length 
of the pedicel till just below the flower, where they become obliterated by transverse 
septa. At the end of the trabecula which lies on the posterior side the single vascular 
strand runs from the peduncle to the flower (vb). Just below the flower it bends 
from a latéral into a central position. It then divides into three branches, which pass 
up the filaments of the stamens. The structure of the vascular bundle is the same as 
that of the leaf, and in the same manner the xylem (1-3 spiral vessels) is directed 
inwards. There is no other thickening. The parenchyma-cells surrounding the lacun:e 
are twice as long as broad, except at a zone a little way below the flower, where the cells 
are rounded. Here also there are no tannin-cells. This Svedelius states is the region 
of detachment of the male flower when it is freed. 
The Flower.—The perianth-leaves are in two whorls, sepals and petals showing various 
differences in structure. The sepals and petals are very similar when young, consisting 
of an epidermis and parenchyma-cells, of which there is only one layer near the margin, 
but in the middle there are 3—4 layers in the sepals and 1-2 in the petals. In the 
sepals there are numerous long tannin-cells near the mediau line ranning longitudinally. 
In the petals there are only a few tannin-cells. When the flower is older every cell of 
the inner upper epidermis of the petals grows out into a projecting papilla. 
The anthers when young are surrounded by two similar cell-layers, the outer of which 
develops every cell intoa projecting papilla when older. These papillee (PI. 36. fig. 18, pp) 
interlock with either those of the adjacent anthers or petals, so that the whole is held 
firmly together and is air-tight. In each of the four loculi of each anther only eight spore 
mother-cells are formed ; they are in a longitudinal column, and in transverse section 
one only is seen. Some of these divide forming a tetrad of pollen-grains; but rin: 
not develop, as there are from 7-14 pollen-grains only in each loculus out of a possibility 
of 32 (PI. 36. fie. 19, D). Pe 
The pollen-grains, jte young, are spherical in shape. When neni jr "eram 
material they are very wrinkled, but the wrinkling may probably be a ra ^i dt 
in alcohol, as no one else mentions it as a peculiarity. They contain three m 
When ripe. 
ANATOMY OF THE FEMALE INFLORESCENCE- 
Peduncle.—When young the female peduncle resembles the male 1 
but Subsequent to fertilization considerable differences (T— 
alterations in structure in the female peduncle which cause it to 
Spiral. : 
n general structure, 
These are due to 
coil up into a tight 
