1112 Thoday.—-The Female Inflorescence and Ovules of 
the outer integument; the figure passes through the base of the embryo-sac, 
and the inner ring of bundles is seen running in the tissues of the fused 
nucellus and inner integument The complex outer integument is already 
differentiated into three zones: (i) the innermost composed of fibrous cells, 
which are unlignified in the very young ovule, but become partly lignified at 
an early stage; (2) a palisade layer; and (3) the outer layer, containing strands 
of parenchymatous tissue each traversed by a bundle, alternating with 
larger strands of cells with brownish Indurated walls. The structure of the 
outer integument shown in this diagram is continued upwards for some 
distance above its level of freedom, and the chief difference as far as the level 
of origin of the inner integument is that in the upper half of the ovule the 
fibrous zone, and consequently the palisade layer, assumes a rayed outline, 
projecting outwards opposite each vascular bundle (Text-fig. 10, p. 1114). 1 
IV. The Seed. 
The seed in both species of Gnetum is straight and cylindrical, cir¬ 
cular in transverse section, and tapering slightly towards the apex where 
a conical projection marks the position of the micropyle. The oldest seed 
of G. africanum among my material was about J-2 cm. long (Fig. 2, 
PL LXXXVI), the single mature seed of G. scandens was about 27 cm. 
in length (Fig. 1 A, PI. LXXXVI). It will be best to describe these seeds 
separately, though their development is similar and the older stages only 
differ in minor details. 
G. africanum . 
Text-fig. 9 is a diagrammatic representation of one of the oldest seeds 
examined ; it is of course possible that further development may take 
place later. 
The nucellus , which is fused for about two-thirds of its length 
with the inner integument, is composed at this stage of a few layers 
of thin-walled parenchymatous tissue. The inner series of vascular 
bundles traverses the fused region of nucellus and inner integument, clearly 
In the region of the integument, and there is no vascular supply to 
any part of the nucellus itself. The latter is almost filled by the 
embryo-sac, which is full of endosperm. The endosperm has a slightly 
corrugated outline, and at the apex of the embryo-sac it projects upwards 
and forms a sort of small ‘ tent-pole 5 2 supporting the tip of the nucellus 
1 Exactly the same stages occur in G. scandens ; but as the lignification of the pith is only 
developed in the upper part of the long stalk of that species it will be realized that the lignified 
tissue which forms the sort of cup at the base of the ovule is there exactly comparable to the cup 
of fibrous tissue at the base of the long-stalked ovule of Bennettites; see pp. 1125, 1126. 
2 Cf. Ginkgo , Seward and Go wan, 1900. 
