486 DR. P. GROOM AND MR. W. RUSHTON ON THE STRUCTURE 
have already been described in the general part of this paper. Here 
attention may be merely directed to the facts that Sanio's rims sometimes 
more or less completely surround the pit-bearing patch on the wall (figs. 43, 
46, 47), also that they may be visible as oblique lines enclosing a single 
pit (fig. 46) and even separating two pits at the same level (fig. 48). As 
the pits become uniseriate near or in the summer-wood and the wall is 
thicker, Sanio’s rims dwindle to mere crescents bounding the upper and 
lower margins of the pit, or one margin only (fig. 44). Proceeding farther 
out in the annual ring, even these vanish and no Sanio’s rims are visible, 
In the summer-wood the pits on the radial walls are scantier and are uni- 
seriate. 
The bordered pits on the radial walls of the spring-wood are oval or circular 
in outline, or slightly flattened where close to a neighbouring pit, and the 
aperture is circular in outline, But in the summer-wood although the pit is 
circular in outline the aperture is short, fusiform, and oblique or nearly 
vertical (fig. 49). 
Pits are not entirely wanting on. the tangential walls, for they occur both 
in the spring-wood and summer-wood, more especially near the slightly bent 
tapering ends of bundles of radially deflected bundles of tracheids, which 
recall the more extensively bent bundles of Pinus Khasya. Oc 'asionally, 
tangential pits occur on the outer walls of the inmost laver of tracheids of 
the annual ring. 
Bordered pits also occur on the rounded ends of some tracheids. Radial 
lignified bars, “ Sanio’s bars," stretching across the lumina of radial rows of 
tracheids also oecur. 
The walls of the tracheids, as seen in radial section, are thicker against 
‘the medullary rays than elsewhere. 
Resin-Ducts. 
The resin-duets are fairly numerous and are almost confined to the 
summer-wood. 
The thin-walled epithelium is surrounded by tissue composed of three 
kinds of cells :— 
i. More elongated parenchyma-cells, with somewhat thicker cellulose- 
walls, which bear large simple oval transversely extended pits. 
ii. Very elongated parenchyma-cells with lignified walls bearing 
obliquely-directed simple pits that are smaller than those on tlie 
- thinner-walled рагепеһуша (fig. 42). 
iii. Parenehyma-tracheids whose lateral walls have bordered pits that 
are circular in outline but have long oblique fusiform apertures. 
Bordered pits occur also on the transverse terminal walls (fig. 42), 
