SEEDLING STRUCTURE IN THE LEGUMINOSA. 63 
ERYTHRINA INDICA, Lam. 
The hypocotyl narrows rapidly to a long tap-root. The cotyledons are 
ovate and very fleshy. 
Only one seedling was available. "This showed a heptareh root, seven 
equal wedge-shaped xylems being arranged round a very large pith. 
Division of each xylem into a triad takes place below the collet, and collater al 
bundles with endarch xylem are rapidly formed from pairs of half-xylems 
beneath each phloem. Apparently three and a half root-poles contribute to 
each cotyledon ; but the point was very difficult to determine accurately, 
owing to the complexity of the structure, ‘secondary thickening, and abundant 
tannin. 
ERYTHRINA ARBORESCENS, Rowb. 
A low tree. The hypocotyl is short and stout, tapering slowly to a long 
root, which is much branched. Cotyledons large and fleshy, turning slightly 
green in the light. Epicotyl tapering upwards, bearing a pair of opposite 
Phaseolus-like leaves. 
3 cm. below the node the root (in the one seedling available) is hexarch, 
but higher up it becomes heptarch. A pith is present throughout. The 
transition phenomena appear to be quite similar to those of “the epigeal 
E. indica, but were extremely difficult to determine. 
VOANDZEIA SUBTERRANEA, Thou. (РІ. 8. figs. 110, 111.) 
An annual creeping herb of rapid growth, with very large seeds which 
ripen underground. Germination is hypogeal. Consequently the hypocotyl 
is very short—about 10 mm.; the diameter along the major axis (it is 
elliptical in section) increases from 2:5 mm. at the collet to 6 mm. at the 
cotyledonary node. The hypocotyl tapers gradually to a long and little- 
branched primary root. The cotyledons remain enclosed in the testa below 
ground, and the plumule develops very early, as is usual in hypogeal species. 
The epicotyl bears a pair of opposite primordial leaves at about 1 em. above 
the cotyledonary node. 
The number and behaviour of the vascular strands vary to some extent 
in different specimens. The root has normally more than four primary 
xylem groups. A seedling with a heptarch root will first be described, and 
then one with a pentarch root. 
(i. The long primary root shows seven practically equal wedge-shaped 
groups of primary xylem which are arranged round a fair-sized pith. "This 
condition continues as far as the external collet, though the pith dilates 
considerably, both here and in the hypocotyl. 
At the collet there are eight groups of primary xylem, the new group 
having arisen by budding off from an old one. The stele becomes elliptical 
here, and the eight groups arrange themselves so that there are three 
