964 Thoday and Ber ridge , — The Anatomy and Morphology of 
The vascular bundles throughout the upper third of the ovule are 
accompanied by large wings of transfusion tissue, which extends some 
distance round the fibrous strands (Text-fig. vm. 2), and at their termination 
the bundles are lost in two large groups of transfusion tracheides (Text-fig. 
vm. 1, t). 
The inner integument , which becomes free about two-thirds of the way 
up the nucellus, projects in the early stages considerably beyond the outer 
covering, but in the mature seed this projecting portion is generally broken 
Text-fig. viii. 1-6. Diagram of series of transverse sections through the ovule of E. distachya . 
P = papillae ; T = transfusion tissue ; 1 = inner integument ; N = nucellus ; c = layer of 
suberized cells at base of nucellus; cross hatching = xylem ; dots = fibres; jagged lines = brown 
tissue. 
off. The whole integument is very thin and its base is made up of thin- 
walled parenchymatous cells only ; in the mycropylar tube there are three 
layers of cells, the inner epidermis, composed of large cells which are cuti- 
cularized to a most remarkable extent (Fig. 11, PI. LXXXV), and two outer 
layers of much smaller cells whose walls are thickened in a minor degree, 
but not cuticularized. A little mucilage appears in the tube shortly before 
fertilization ; later this becomes hardened into a solid mass 1 which closes 
1 A similar secretion of mucilage is recorded by Pearson (’ 06 ) at the fertilization stage 
in Welwitschia\ but it does not appear to be known whether this persists and becomes hardened 
afterwards. 
