963 
the Inflorescences and Flowers of Ephedra. 
PI. LXXXV, and in Text-fig. VII. 2. Here the common wall of integumental 
tissue between the two nucelli is incomplete, and the small nucellar mass 
of the abortive ovule is fused at its apex with the fertile nucellus, so that in 
this section it appears as a long lobe of the latter extending downwards into 
the integumental tissue. 
In a somewhat similar case (Text-fig. VII. 3) fusion of the two nucelli 
has only taken place at their extreme apices, and the common integumental 
wall runs up between them and ends in a small free lamina in the chink 
below the point of fusion. Here again only one nucellus contains a pro- 
thallium with archegonia. 
Fully one- third of thirty-four strobili of E. altissima examined showed 
traces of the presence of a second abortive ovule within the outer integu- 
ment. 
(e) The Anatomy of the Ovule . 1 
E. distachya . The ovules in E. distachya and other biovulate species 
are roughly triangular, compressed and flattened on their adjacent sides, 
but rounded abaxially. 
Two vascular bundles traverse the outer integument, running in the 
two sharp angles of the flattened side. The outer epidermis of the integu- 
ment is composed of large columnar cells and the inner epidermis of similar 
smaller cells except where it clasps the micropylar tube ; there each cell 
is drawn out into a papilla. In the old ovule these become lignified and are 
firmly fused on to the micropylar tube (Text-figs. VIII and IX and especially 
XI. 3, and Fig. 1 1, PI. LXXXV). 
At the base of the integument it consists mainly of a layer of brown 
cells underneath the outer epidermis, which is continuous right round the 
bundles (Text-fig. vm. 5), and internal to this is a band of tissue which even 
in the oldest ovule examined was still parenchymatous. 
A little higher up (Text-fig. VIII. 4), fibrous cells with thick walls become 
differentiated in this parenchymatous band, and very soon there is a thick 
layer of fibrous cells on the inner side of the brown layer (Text-fig. VIII. 3). 
In the upper part of the outer integument there is, as well as the fibrous 
layer, a more conspicuous strand 2 of larger fibrous cells accompanying each 
vascular bundle on its inner side (Text-fig. VIII. 2) ; but at the tip, where the 
integument surrounds the micropylar tube, both the fibrous layer and the 
separate strands die out (Text-fig. VIII. 1). The brown layer gradually 
diminishes in prominence till in this region it is represented only by two 
small bands of tissue alternating with the two vascular bundles. 
1 Strasburger, 1872, pp. 86 ff., PI. XVI, &c. 
2 In E. nebrodensis , the outer integument of which is very like that of E. distachya , these 
fibrous strands accompany the vascular bundles right to the base of the integument. The fibrous 
layer is also well marked and strongly lignified. 
