1 6 Oliver and Salisbury. — On the Structure and 
perhaps to converge suddenly later to a single strand. Another section 
(R. 1 15- 2 ) which gives food for speculation passes tangentially through the 
stalk. This shows what may have been a cupule containing a vascular 
strand. A peculiar feature of this preparation is that the plane of section 
should theoretically (if the seed be borne vertically on a straight stalk) pass 
through the axis of the stalk, but actually it cuts the stalk or cupule, as the 
case may be, tangentially and passes out on the same side ; therefore either 
the stalk in this instance was bent or else the seeds in this species were 
borne in a cupule in a similar manner to the closely allied seed Gnetopsis 
elliptica , where the insertion of the seeds and cupule is oblique to the main 
axis . 1 The continuity is not convincing, but the fact that the possible 
cupule contains secretory canals suggests that the section R. 1 1 3 may have 
been cut through the stalk at the base of the cupule, which would account 
for both the difficulties of its acceptance. In any case we ourselves regard 
the present evidence as quite inadequate for a definite decision. 
7. The Nucellus . 
This, the central body of the seed, requires detailed description in view 
of the unusual and possibly significant elaboration of structure shown by 
its distal portion which was concerned in the reception and storage of the. 
pollen. 
The nucellus falls into three regions : — 
(1) The lagenostome , a structure evidently corresponding with the 
pollen-chamber of such a seed as Lagenostoma Lomaxii. It lies in a saucer- 
like depression at the summit of (2) the plinth , which forms the truncated 
continuation of (3) the main body of the nucellus or megaspore chamber. 
The lagenostome and plinth, though closely invested by the integu- 
mental lining (‘ micropylar funnel ’ and ‘ plinth jacket ’), were free from the 
integument ; the megaspore chamber, which extends from the chalaza to 
the level at which the apical tapering of the seed begins, shows on the other 
hand complete coalescence with the testa. 
The horizontal septum separating the plinth cavity from the megaspore 
chamber is formed by the tapetum, and may for convenience of reference 
be termed the tapetal septum (cf. Text-fig. 3). 
8. The Lagenostome and Plinth. 
These two organs were so intimately related that it will be convenient 
to deal with them in the same section. The plinth is the tapering free 
end of the nucellus, on the flattened end of which the small urceolate 
lagenostome was inserted in a shallow, saucer-like depression. Apart from 
the remains of its internal filling tissue, to which reference will shortly be 
made, the plinth is as a rule in our specimens represented by its epidermis — ■ 
1 Renault : Cours de Bot. foss., vol. iv, PI. XX, Fig. 1. 
