4 BOTANICAL GAZETTE [yury 
rings. It is to be observed from the photograph that the annual 
rings are not as strongly marked as they are in pines of the present 
day. This feature is due to the less pronounced thickening of the 
tracheids of the summer wood. There are no parenchyma cells 
present in the wood except those which surround the resin canals. 
The rays are strongly marked on account of the resinous character 
of their contents, a feature of difference from modern pines, where 
as a rule the ray-cells are quite free from the dark brown secretion 
which is characteristic of the resiniferous cells in the Cupressineae 
and in the genera Cedrus and Tsuga among the Abietineae. The 
resin canals show a tendency to become aggregated in clusters. They 
may be almost absent in one or more annual rings and correspond- 
ingly abundant in others. The resin ducts are surrounded by highly 
resiniferous cells and appear not to be confined to any special region 
of the annual ring. On the left of the figure is to be seen a resin 
canal occluded by tyloses. 
Fig. 2 shows a section of the same branch which includes a portion 
of the pith. The medullary cells are filled with dark brown contents. 
Sclerified cells are quite absent in the pith. To the right of .the 
photograph a process passes off from the medulla, which is the pith 
of a small branch, in all probability a brachyblast or short shoot. 
In the wood immediately adjoining the pith may be seen a number > 
of resin canals, closely filled with tyloses. The position of these — 
resin canals in relation to the pith is that found among living species 
of Pinus, in the hard pines (Scleropitys auct.), in which the resin 
canals also abut on the pith, in some cases actually occurring in 
the primary wood, in contrast to the soft pines (Malacopitys auct.), 
where the resin ducts are somewhat remote from the pith and never 
occur in the primary wood. The annual rings are generally less” 
well marked in proximity to the medulla than in the more external 
part of the wood. 
Fig. 3 is a longitudinal radial view of the wood of the same speci- 
men illustrated in the two preceding photographs. The section 
shows a single vertical and several anastomosing horizontal resin 
canals, all quite filled with tyloses. A careful inspection indicates 
that the wood is made up of tracheids, which are provided with 
a single vertical row of radial bordered pits. : 
