Female Strobilus in Podocarpus . 527 
persist as a point (Fig. 4, lam. f br.) or become quite merged with the 
tissue of the ovuliferous scale (Fig. 6 , lam.f. br.). 
Histology. In a longitudinal section of a strobilus in the gametophyte 
stage (Fig. 8) the lamina of the bract is seen to have the apex quite distinct 
with two lines of stomata. A single normally orientated vascular bundle, 
starting from a plate of tracheides under the epidermal tissue, runs down the 
whole length of the fertile bract to the swollen base. It is accompanied by 
a resin canal with well-developed epithelium (Fig. 8 c , epi.) on the dorsal 
side. A well-marked cuticularized epidermis with a hypodermal sclerotic 
layer (Fig. 8 a , h. f.) covers the lamina of the bract, and is continued un- 
interruptedly round that of the ovuliferous scale. 
This sclerotic layer is also present in the foliage leaves of both 
cupressoid and imbricate forms, being only interrupted by the stomata, 
which occur in four rows, two on the ventral and two on the dorsal faces, and 
seems limited in Podocarpus to § DACRYCARPUS. Thomson ( 56 , p. 349) 
records a hypodermal sclerotic layer for the megasporophyll and the 
vegetative leaf of Microcachrys. 
The swollen base of the bract is limited by the verruculose out- 
growths (Fig. 8 b) which densely cover this portion. They may also 
characterize the base of the ovuliferous scale (Fig. 5), which is modified 
like the bract bases, fusing with them completely. This figure is taken 
from a strobilus on a tree in the Singapore Botanic Gardens, which was 
covered with young cones in December. Mr. Ridley informed me that this 
tree never set seed. The ovules proved all sterile, showing no proper nucellus 
formation. The epidermal layer of these bract bases is cuticularized, and 
the cells show dense tannin contents like those of the lamina, but there 
is no hypodermal sclerenchyma. The other cells are thin-walled, large, 
and practically devoid of contents. They suggest water-storage tissue, and 
this may possibly be the function of the so-called swollen ‘ receptacle ’ 
throughout the genus. This tissue is well developed, as we have seen, in 
post-pollination (Figs. 2, 3, 4, and 7), and increases in size with the growth 
of the ovule, the increase being due to proliferation of the mesophyll cells. 
The structure of the sterile bract resembles that of the fertile. The 
lamina shows a cuticularized epidermis and hypodermal fibrous layer, and 
the vascular bundle terminates in a group of tracheides and is accompanied 
by a resin canal with epithelium. The swollen base is equally verruculose. 
These swellings are characteristic of § DACRYCARPUS and possibly increase 
the surface of the water-storage tissue, which is much less developed in this 
section than in § EUPODOCARPUS, and is entirely absent in § NaGEIA and 
§ Stachycarpus. 
The ovuliferous scale completely encloses the ovule, and is fused with 
the integument throughout its whole length, except in the region of the 
micropyle. It shows the same structure in its epidermal, hypodermal, and 
