Female Strobilus in Podocarpus . 
529 
The nucellus is much contracted in all material at this stage (Fig. 8, 
nuc . ), but pollen-tubes can be traced in the apex, whose development, 
judging from other material, would coincide with free nuclear division 
in the female gametophyte. 
In Fig. 6 a longitudinal section of the ovule in the archegonium stage 
shows the lamina of the fertile bract no longer so distinct, it having elongated 
and stretched with the growth of the ovuliferous scale ; it is served by one 
bundle with normal orientation arising from a hypodermal group of tracheides. 
The mesophyll cells show lignified thickening of the cell-walls, reacting to 
phloroglucin (Fig. 6 c). This lignification is also seen in the mesophyll of 
the ovuliferous scale, in which the two vascular bundles, on expanding 
in a ring round the base of the ovule, send secondary branches into the 
lamina of the scale. This development, which marks a later stage than 
shown in Fig. 8, extends half-way down the lamina which surrounds the 
ovular tissues (Fig. 6, in. v. b. o.s.). 
The nutritive cells of the integument and nucellus show considerable 
increase in number (Fig. 6, tan. and st. c.) and the micropyle is closed, 
a result effected by proliferation of tissue in the basal portion of the ovuli- 
ferous scale and the elongation of the lamina of the same. The integu- 
ment shows slight peripheral lignification of the cell-walls. 
The cells of the stigmatic apex of the nucellus show dense starch 
contents. Stopes and Fujii ( 51 , p. 11) note in Pinus the deposition of 
starch in considerable quantities in the tip of the nucellus, in very young 
ovules in which archegonia were not present. This is also the case in 
Podocarpus (Fig. 6, nuc. st.). Starch is initiated with the formation of the 
macrospore, and its presence is no doubt related to the growth of the pollen- 
tubes, which, however, do not absorb it entirely, as some is generally present 
even when the nucellus itself is reduced to this apical portion, which persists 
as a cap to the prothallus (PI. L, Fig. 38, nuc. cap). The periphery of the 
nucellus is marked by large cells with very little contents, whereas the two 
or three parietal layers of smaller tabular cells which surround the female 
gametophyte, and are constantly being absorbed by the growth of the 
latter, show large and active nuclei and denser staining contents, forming 
a well-marked tapetum. 
Coker ( 15 , p. 103) in P. coriacea records the complete absence of 
any tapetum and ‘ spongy layer but in the present investigation it was 
found in every species from the earliest stages till the laying down of starch 
in the prothallus and in embryo development. 
The female gametophyte has increased at the expense of the nucellus, 
and in this stage contains five archegonia. These are situated at the apex 
of the prothallus, and are very long and attenuated, each being surrounded 
by a well-marked jacket layer of denser staining cells with large and 
active nuclei. Archegonia are separated from one another by sterile 
