SEEDLING STRUCTURE IN THE LEGUMINOSJE. 41 
pith begins to appear just above the collet, and by its gradual broadening 
breaks the xylem into two cotyledonary traces which have a narrow V-shape. 
The metaxylems collect into two groups on the sides of each polar protoxylem, 
and the phloems (which have undergone no change save tbe loss of their 
fibres at the collet) now lie on the flanks of the double xylem bundle so 
formed. In this position the vascular tissue enters the cotyledons, and 
gradually changes, as it ascends the petiole, until the xylem is completely 
endareh and the two phloems have fused dorsally above it; this happens in 
the region of branching of the veins. 
GALEGA OFFICINALIS, Linn. 
Erect perennial herb. Cotyledons spathulate-oblong. De Candolle (1825, 
pl. 8) gives a figure. 
The material examined was unsatisfactory, owing to extensive secondary 
thickening. The structure appeared to show considerable similarity to 
G. orientalis. The root was apparently tetrarch, becoming diarch above, and 
the transition was high ; but the material hardly admitted of complete 
certainty in the examination of the primary structure. 
CoLUTEA CRUENTA, Dryand. 
Fair-sized shrub. Hypocotyl tapering slowly to the long primary root. 
Cotyledons ovate. 
The root is tetrarch, xylem being solid to the centre. A pith begins to 
appear just below the external collet, and slowly dilates as we ascend the 
hypocotyl. The xylem arranges itself in four similar tangential groups, each 
of which carries with it a pair of phloems arisen by the division of the four 
root-phloems. Not until 2 mm. below the node do the lateral xylem groups 
divide in half and pass to join the polar xylems ; the latter here consist of 
three groups each, a median protoxylem and two metaxylem wings with 
superposed phloem. Just below the cotyledons fusion of the half-bundles takes 
place ; and at the node each cotyledon trace consists of two broad collateral 
bundles, with a conspicuous group of crushed polar protoxylem lying between 
them, and small patches of lateral protoxylem on their extreme edges. 
CoLUTEA ARBORESCENS, Linn. (Pl. 1. fig. 14.) 
Shrub of 2-3 metres. Base of hypocotyl somewhat swollen beneath the 
ground and tapering rapidly to root. Cotyledons large, leaf-like, ovate, 
slightly secund. De Candolle (1825, pl. 11) gives a figure of the seedling. 
The transition is essentially similar to that described in C. cruenta. 
CARAGANA ARBORESCENS, Lam. (Pls. 6. fig. 90 ; 7. figs. 91, 92.) 
Fair-sized shrub. Hypocotyl passing smoothly into the little-branched 
