449 
Stiles . — The Podocarpeae. 
Most species of Podocarpus are dioecious, though there are cases of 
monoecism in the genus. Mr. Saxton has made some interesting records 
when collecting material for this investigation. He found that P. latifolius 
was normally dioecious, but a single case was found of a female plant which 
bore a single male cone. In the locality in which this record was made 
male trees were found to be much more numerous than female ones. 
It should be noted that P. neriifolius , Don, is perhaps more usually 
called P. bracteata , Blume ; similarly P. salignus , D. Don, is possibly better 
known as P. chilinns , L. C. Rich., while P. Thunbergii , Hook., is the more 
familiar name of P. latifolius , (Thunb.) R. Br. The plant which figures 
most in past investigations of the genus is Podocarpus chinensisy Wall, (or 
P. sinensis ). Following Pilger this is P. macrophyllns , subsp. maki , Sieb. 
Of the 63 species enumerated by Pilger, 3 are placed by that writer in 
D aery carpus, 1 in Microcarpus , 4 in Nageia , 10 in Stachycarpus , and 34 in 
Eupodocarpus. The remaining 1 1 species are ‘ species incertae sedis \ 3 of 
them possibly belonging to Nageia and 8 to Eupodocarpus. This fact alone 
shows the imperfect state of our knowledge of the genus at the present time, 
and it is possible that future systematic study may considerably alter the 
number of species. 
iv. Stems. 
A. Primary Structure. 
The primary structure of the stem has been examined in the following 
species : Dacrydium Franklini , D. cupressmum , Podocarpus nagi , P. elonga- 
tus y P. amarusy and P. andinns. 
A transverse section through the young stem of Podocarpus andinus 
is roughly circular, and shows generally about four of the decurrent leaf- 
bases (PI. XLVI, Fig. 1). There is in the stem a ring of seven or eight endarch 
collateral bundles. The centre is occupied by a parenchymatous pith ; in 
the cortex is a ring of resin canals just outside the ring of bundles, one 
resin canal appearing just outside the phloem of each vascular bundle. In 
this species the resin canals of the stem are fairly large structures with 
a well-marked epithelial layer, and the canals are no doubt functional. The 
protoxylem, as usual, consists of spirally thickened elements, while the cells 
of the metaxylem have uniseriate bordered pits. The cortex is composed 
of parenchymatous cells ; stone cells were not observed. 
A leaf-trace arises by the division of one of the bundles, so that the 
two resulting bundles lie side by side in the ring. This is followed by the 
division of the resin canal in a similar manner. The leaf-trace and its 
accompanying resin canal then pass upwards and outwards into the 
leaf base. 
Podocarpus elongatus is on the whole similar. A transverse section of 
the stem of this species is roughly square (PI. XLVI, Fig. 2, and Text-fig. 1, b). 
