1908] BURLINGAME—PODOCARPUS 165 
of a longitudinal section somewhat to one side of the middle, and 
will give an idea of the side view, as well as the relation of the sporan- 
gial cavity to the sterile portion of the leaf. Fig. 6 shows a cross- 
section of a sporophyll near the middle of the sporangium. The 
sporangia are somewhat less prominently exposed on the under side 
than those of Pinus, for example. A single weakly defined vascular 
bundle (fig. 6) traverses the upper part of the central sterile septum 
and is sometimes accompanied by a resin canal lying below it and 
between the sporangia. The wall of the sporangium varies in thick- 
hess somewhat, but in general on the freely exposed part it is about 
four or five cells thick (fig. 5). One or two.of the. inner layers are 
slightly differentiated as a tapetum. This is not very evident and 
does not occur until the sporogenous tissue has nearly reached the 
mother cell stage. The tapetum does not long persist, but disap- 
pears as a functional tissue about the time the young spores have 
formed a thick wall and wings. All of the wall proper, except the 
outermost layer of thickened cells, may break down before the spores 
are shed, 
The earliest stages of the sporogenous tissue observed (in P. sp.) 
lacked one or two divisions of the mother cell stage. Fig. 7 will serve _ 
as a typical Tepresentative cell of the sporogenous tissue at this stage. 
The walls are thin and delicate, as is usually the case, and the cyto- 
plasm stains somewhat more densely than that of the wall cells. It 
Was possible to secure very good preparations of this, considering 
the nature of the killing and fixing agent. The cells were slightly 
Strunken, so as to have pulled away in many places from one another 
or from their own walls. F ig. 7 will show the principal facts. The 
‘ytoplasm does not seem to present either a typically reticulated or 
- Structure, but rather resembles a sort of flocculent precip- 
pes scattered more or less irregularly through the cell. These floc- 
an masses May assume a sort of feathery, filamentous, sieniista 
ee agape form, or they may appear as scattered masses of irregu- 
‘iia The filaments and other masses do not seem to be con- 
b iM any definite manner, but to be distributed through the cell 
Y chance, No stored food can be detected microscopically in the 
Yioplasm at this time, though the parenchymatous cells of the axial 
Portion of the strobilus contain considerable quantities of large 
