484 DR. 0. STAPF ON SARARANGA SINUOSA. 
channel, in the advanced state which the flowers examined by 
me were in, is generally closed by the walls of the channel 
being tightly pressed against each other. A longitudinal 
section through the pore shows that the striated and thick 
cuticle of the epidermis surrounding the mouth continues down 
the channel to the point near its base, where it widens again. 
The epidermis itself and the collenchyma below the mouth are 
also essentially the same as at any other point of the gynaeceum. 
At the base of the pore, however, the epidermis as well as the 
tissue immediately below it consists of smaller thin-walled 
isodiametric cells, full of plasma and having large nuclei 
(Pl. VII, fig. 24, e). The outer walls of the epidermis of this 
part are also quite thin and the cuticle delicate. Below this 
point the tissue continues somewhat rich in plasma for some 
distance; but the cells become gradually larger and morc 
oblong (PI. VII. fig. 24, ct), passing finally into the parenchyma 
which fills the space between the double rows of ovary cells. 
The cavity at the base of the pore sometimes expands, as 
mentioned above, a trifle in the direction of the stigma-rows, 
whilst a narrow band of a compact small-celled parenchyma 
extends in the same direction, joining the basal portions of all 
the pores with each other and with the similar tissue that 
surrounds the vascular bundle. The walls of the epidermis 
cells at the base of the pores suberize soon, though later than 
the stigma, and then stain purple readily with phloroglucine 
and chloric acid. I was led to a closer examination of these 
conditions by my desire to ascertain the actual function of the 
stigma, and of the sutural pore, and the way by which the 
pollen tubes reach the cavity of the ovary cell. The specimens 
at my disposal were, however, either too advanced or not 
fertilized at all. In no case did 1 succeed in actually tracing 
the pollen tubes in their descent to the ovule, although I once 
found two pollen grains close to a stigma, one empty and the 
other with the exine split, and the intine just bulging out. The 
pollen grains observed (Pl. V. fig. 4) were similar to those of 
Pandanus fasciculatus (Pl. V. fig. 5), and I have very little 
doubt that they were really pollen of a male Sararanga. This 
phase in the fertilization is still very obscure in Pandanus. 
Solms-Laubach points out that a proper stigmatic channel is 
present in Pandanus pygmeus, whilst a conductive tissue is 
said to extend from the ovary cell towards the stigma in the 
