Female Strohilus in Podocarpus. 563 
function of these cells apparently ceases and the walls gradually lignify, 
areas being left where phloem strands penetrate to the nucellus. 
In P. ferruginea these tannin cells are organized in regular super- 
posed layers, laterally elongated, which surround the integument. 
The nucellus, composed of larger and less compact cells, is also charac- 
terized by a smaller zone of tannin cells. Before pollination the apex shows 
rows of loose stigmatic cells, which catch the pollen-grains. These cells 
subsequently become crushed on the elongation of the tubes ; the latter are 
often exposed in consequence. 
No pollen-grains or cases of penetration by pollen-tubes were observed 
from any portion of the nucellus other than the stigmatic apex. 
In § Nageia and § Stachycarpus, also some species of § Eupodo- 
CARPUS, the apex of the nucellus is very much elongated. 
From the pollination stages starch is present in the cells of the apex in 
all species, and the walls often show thickening. 
A well-differentiated tapetum of several layers is present in all the 
species examined, the cells with active nuclei and denser contents showing 
continuous disintegration in the outer layer, from the development of the 
megaspore to the absorption of the body of the nucellus by the female 
gametophyte. 
Tetrad formation was not seen. 
In megaspore formation the nucleus divides, a parietal layer of free 
nuclei surrounding the central vacuole, which gradually fills up with 
prothallial tissue. Further stages were not traceable, owing to contraction 
of tissue, but are evidently paralleled with Coker’s results on P. coriacea 
and similar development in the Abietineae. 
A megaspore membrane of two layers was observed in all the species 
surrounding the developing prothallus, which persists till the embryo 
stages. In P .polystachya it was not traceable with certainty in the embryo 
stage. 
The female prothallus at fertilization consists of a central cylinder 
of small elongated and rectangular cells, and large, mostly binucleate, poly- 
gonal cells extending to the periphery, and it is limited by an epidermal 
layer of small uninucleate cells, with denser contents and active nuclei. 
The number of archegonia seen was five to seven. 
The archegonia, arranged in one or two groups, are very long and flask- 
shaped. The neck consists of two to six cells, and they are each surrounded 
by a single layer of jacket cells. 
In one case two archegonia were enclosed in one jacket. 
No ventral canal cell was seen. 
Sterile prothallia, with a cavity replacing the archegonia, were observed. 
In one case no tracheides were present, but on two occasions well-developed 
tracheides were found in the central cylinder of small-celled tissue. 
