SEEDLING STRUCTURE IN THE LEGUMINOS/E. 45 
protoxylem was observed. The cotyledon trace at the node consists of 
phloems and xylems in a tangential row ; but the transition is completed by 
the bundles becoming collateral very shortly above the node. 
OXYTROPIS LAPPONICA, Gaud. 
A herbaceous perennial, sometimes with stems not developed, at others 
with stems a few centimetres long. The cotyledons are small and ovate. 
The transition phenomena are closely similar to those in O. campestris. 
BisERRULA PELECINUs, Linn. 
Many seedlings arise from a long indehiscent fruit, The cotyledons are. 
ovate and leaf-like. 
The transition is quite like that in the O.ytropzs spp. 
HEDYSARE.E. 
ARACHIS HYPOG.EA, Linn. 
A small annual herbaceous plant with diffuse stems producing large seeds 
which ripen underground. The embryo is straight. The cotyledons are 
stout and fleshy, ovate with a cordate base ; on germination they are pushed 
up above ground, but serve almost entirely for food-storage. The hypocotyl 
is short and thick, 7 mm. in diameter at the base, 6x4 mm. at the oval 
summit, with a marked constriction below the collet leading to the narrower 
primary root. De Candolle (1825) gives a figure of the seedling. 
The root is tetrarch, the xylem consisting of a solid mass of large pitted 
vessels with four radiating protoxylem arms. The phloems contain a large 
quantity of scattered fibres. At the dilation of the axis below the external 
collet a large pith appears ; the metaxylem moves into a tangential position 
and forms wings on either side of the four long narrow 1-3-seriate proto- 
xylem plates. Immediately above the collet the metaxylem wings of the 
polar groups move tangentially and fuse with the lateral groups ; the latter 
having, with their protoxylems, divided, Thus four main groups of xylem are 
found at approximately equal distances; over each of these lies a phloem 
group, so that the axis at this point would have a stem-like structure but for 
the vestigial polar protoxylem at each end of the elliptical stele. 
Plumular bundles new begin to appear ; they detach themselves from the 
four main metaxylem groups laterally to the stele, so that it is difficult to 
determine whether the lateral root-poles are cotyledonary or plumular. As 
they appear the ellipse elongates considerably : 2 mm, above the external 
collet the first plumular bundles are given off ; half-way up the hypocotyl 
there are three on either side. The cotyledon traces have also become more 
complex, and each consists of the median vestigial protoxylem and four 
collateral bundles. Higher up still the bundles supplying ach cotyledon 
have again fused into two broad bands, and in this condition they enter the 
cotyledons ; the plumular bundles have increased by branching into five on 
