20 MR. R. H. COMPTON: AN INVESTIGATION OF THE 
difficult to determine. The cortex and pith in the hypocotyl, and to a greater: 
extent in the cotyledons, contain many tannin-sacs. 
Half-way up the hypocotyl the pith has further increased in diameter at 
the expense of the cortex. The bands of fibres now extend in a continuous. 
ring all round the stele, even over the position of the root protoxylems. The 
xylem is now in the usual four triads, but the total bulk is diminished. The 
lateral triads are somewhat more spread out tangentially than are the polar. 
This structure is maintained to within 3 mm. of the cotyledonary node. Each 
of the root protoxylems then divides, and the halves join their respective 
metaxylems. The polar metaxylems give off external branches, the internal 
parts then fusing in the median plane, so that three bundles are found at each 
end of the stele, 1 mm. below the cotyledons. Meanwhile the phloem has 
united over the ends of the ellipse, so that instead of four arcs there are now 
only two long bands. The lateral groups of metaxylem and protoxylem. 
separate somewhat from one another, but do not fuse with the polar groups. 
before entering the cotyledons. Thus each cotyledon receives five endarch: 
groups of xylem, three of which are derived from the polar, and two from 
the lateral root xylems ; over all extends the continuous band of phloem and: 
fibres. 
The absence of fusion between lateral and polar xylems is no doubt 
connected with the large size of the cotyledons and their broad insertion on 
the hypocotyl. 
* ж * * * 
So far as could be judged from imperfect material, Poinciana regia, Boj., 
agrees fairly closely with C. pulcherrima. 
JZSALPINIA SAPPAN, Linn. 
A small tree. The hypocotyl is almost absent, there being only about 
1mm. of epidermis below the cotyledons. There is a long primary root. 
The cotyledons are borne on stalks a few mm. in length; the laminas are 
thick and are fused together by their ventral faces. The plumule develops 
immediately upon germination and produces a long tapering internode. 
The root is tetrarch, and contains four large solid xylem wedges sur- 
rounding a fair-sized pith. A zone of fibres bounds each of the four phloem 
groups externally. 
The mode of transition is almost identical with that found in the epigeal 
Cesalpinia pulcherrima, with the difference that since the hypocotyl is here 
extremely short the transition phenomena are compressed into a very short 
distance. The tangential position of the xylem is attained 1 mm. below the 
cotyledons. 0'5 mm. below the cotyledons we find the lateral metaxylems 
and protoxylems separating towards the poles, the terminal groups remaining 
continuous. Immediately below the node each polar xylem divides into two 
