24 MR. R. H. COMPTON: AN INVESTIGATION OF THE 
eighths up the hypocotyl the polar xylems are broadly T-shaped in section, 
and each lateral group is on the point of dividing into two tangential bands 
(fig. 65). At the node these half-laterals attach themselves lightly to either 
side of each polar xylem, but do not fuse completely (fig. 67). Thus the 
base of the cotyledon appears to have only a double bundle, which, however, 
quickly resolves itself into its components higher up. 
PULTENZA DAPHNOIDES Wendl. (Pl. 4. figs. 62, 63, 66, 68.) 
Hypocotyl tapering slowly to the root. Cotyledons oblong-ovate. Early 
leaves in opposite pairs. 
The root is tetrarch, as in Viminaria denudata (fig 62) ; a pith begins to 
appear about a quarter of the way up the hypocotyl, dilating the xylem, the . 
condition of fig. 63 being reached about half-way up the hypocotyl. The ring 
of xylem then breaks into four groups: the two polar ones being broad and 
tangential but still exarch, consisting of proto- and metaxylem ; the lateral 
ones dwindling and consisting of exarch protoxylem only (fig. 66, at three- 
fourths up the hypocotyl). The polar xylems break into tangential triads ; 
the laterals disappear completely at seven-eighths up the hypocotyl, and do 
not contribute to the cotyledons. Hach cotyledon receives a pair of collateral 
bundles and a small median protoxylem all close together (fig. 68). 
Plumular traces consisting of secondary xylems appear in the upper part of 
the hypocotyl immediately outside the dwindling lateral root protoxylems, but 
having no direct continuity with them : at certain levels, in sufficiently young 
seedlings, sections show neither root-pole nor epicotyledonary bundle ; they 
come into contact with one another, however, when the plumule begins to 
develop. 
CHORIZEMA CORDATUM, Lindl. 
Hypocotyl tapering gradually to the root. Cotyledons linear-oblong. 
The account given for Pultenwa daphnoides applies to this seedling also, with 
slight differences in detail. Pith does not begin to appear till about 5 mm. 
below the cotyledons, so that the changes are relatively compressed. 
Baptista LEUCANTHA, Torr. j Gray. (Pl. 4. figs. 61, 68.) 
Hypocotyl tapers slowly to the root. Cotyledons rather fleshy, ovate, 
somewhat asymmetrical (owing to accumbency of radicle in seed). 
The root contains a diarch biseriate plate of vessels, and two lateral bands 
of phloem without fibres (fig. 61). At the external collet the xylem 
plate broadens internally, and just above this level a pith appears and the 
xylem plate separates into two halves. Half-way up the hypocotyl each 
xylem has a V-shape, but the apical protoxylem is slightly separated from the 
lateral metaxylem arms of the V. The phloems have also divided, and lie 
