40 
Thoday. — Anatomy of the Ovule and Seed in 
ingrowth of the inner epidermis of the micropylar tube. Photo 15, PI. I, 
shows the tip of this ovule. 
Each of the others had a small flange composed of a few hairs in which 
the tip of the outer integument was buried. In one of these the lumen of 
the micropylar canal was still open, although the ingrowing epidermal cells 
had almost everywhere divided once and the epidermal layer three or four 
times. In another the flange was more developed and the wall of the tube 
thicker. The epidermal cells that grow out to form the flange had already 
divided into radial rows, as figured by Miss Berridge . 1 The middle cover- 
ing in this ovule had thickened and the formation of the expanded shoulders 
was already beginning. 
In these young ovules there is much mucilage, both in the lumen and 
in the cavity between the micropylar tube and the nucellar apex. The 
nucellar apex is composed of rows of cells radiating outwards, and de- 
generating in the region of the pollen-chamber. Photo 16 , PI. I, shows 
the degenerating .tissue above the radial rows of cells in the nucellar apex. 
Seeds about 8 mm. long . The two seeds about 8 mm. long were only 
a little more advanced than the stage described by Miss Berridge (1911), 
and their structure is easily comparable with that shown in her Fig. 3 . 
Near the apex of the micropylar tube the upwardly directed tissue growing 
out from the wall of the micropylar tube was more sharply marked than in 
Miss Berridge’s Fig. 3 , and appears as a free ring in transverse sections 
above the level of its origin from the tube. In this region the proliferated 
wall of the now closed micropylar tube is composed of clearly distinguishable 
and beautifully regular rows of cells, and is brought closely into contact 
with the outer covering; indeed in some places their boundaries aie 
indistinguishable. The growth in thickness of the micropylar wall as 
a whole has resulted in the closing both of the cavity between it and the 
outer covering and the lumen itself, which is now quite obliterated. 
In the lower part of the closed portion of the tube the wall is narrower 
and the cavity tends to reappear, but is blocked by a solid mass of pro- 
liferated epidermal cells which have grown out more irregularly as papillae 
with enlarged ends and are now strongly lignified, thus forming a very con- 
spicuous rod of cells, something like, though much more developed than, the 
core described in G. scandens , and figured in a former paper. 2 
Just below this papillate region the open tube has a cuticularized 
lining ; near the bottom of the lower flange the lining is torn, but the tube 
is nowhere broken across. 
When the level is reached at which the tube is supported by the tip of 
the middle covering the lining is again entire and cuticularized. The tip of 
the middle covering is still buried in the hairs of the downwardly projecting 
flange. 
1 Berridge, 1911, p. 140 . 
2 Thoday, 1911 ; Fig. 9 , PI. LXXXVI. 
