SEEDLING STRUCTURE IN THE LEGUMINOSÆ. 43 
1:0-1'1 mm., while in tetrarch it is l:1-1:2 mm. ; it is possible that this 
variation is connected with the variability in position of the radicle within 
the testa. So slight is the difference in diameter, however, that it is 
suggested with hesitation that it may be connected with the variation of 
symmetry. In Doryenium hirsutum, more variable still in anatomy, no such 
variation in diameter was detected. 
CARAGANA TRAGACANTHOIDES, Poir. 
Shrub or small tree. Cotyledons ovate, shortly stalked. 
The root is triarch in the only seedling examined, becoming tetrarch 
several mm. below the collet. The xylem is in four narrow wedge-shaped 
groups, surrounding a pith, which appears to be present throughout. 
Above the collet the features of the anatomy closely resemble those in 
С. arborescens, 
ASTRAGALUS CHLOROSTACHYS, Lindl. 
A copiously branched undershrub, several feet high. The cotyledons are 
stalked and twisted to one side, uniting to a short tube which bears the 
axillary buds. 
The root is triarch, containing a small solid xylem star, and three phloems 
without fibres. A pith begins to appear at the collet region, but dilates 
slowly, so that not till two-thirds up the hypocotyl do we find the xylem 
forming the usual complete ring with three projecting protoxylems. In the 
upper third of the hypocotyl, however, changes are more rapid. The xylem 
ring breaks in the intercotyledonary plane, and at the same time new 
protoxvlem elements make their appearance on the side opposite the third 
(lateral) protoxylem, Thus the separating cotyledon traces appear to have 
been derived from a tetrarch root. The three protoxylem groups—polar and 
two half-laterals—of each cotyledon bundle are quite conspicuous, and 
persist above the cotyledonary node. The double bundle at the node consists 
of obliquely collateral groups of xylem and phloem between which the polar 
protoxylem persists. The fusion of phloems takes place just above the region 
of branching into the lamina. 
CARMICHAELIA AUSTRALIS, №. Br. 
An erect almost leafless shrub. — Cotyledons stalked, ovate, slightly 
secund. 
The root is triarch, containing three equal 1-2-seriate xylem plates meeting 
at the centre. These separate and become wedge-shaped, arranging them- 
selves round a pith, so that the two polar xylems are more than 120° apart. 
A little more than half-way up the hypocotyl the phloem between the polar 
xylems divides; and about 2 mm. below the cotyledons a fourth xylem. 
appears between the two half-phloems, so that tetrarchy is established. 
