48 MR. R. H. COMPTON: AN INVESTIGATION OF THE 
ScoRPIURUS SUBVILLOSA, Linn. 
Has been investigated in detail by Dangeard (1889, p. 108) ; it appears to 
present no noteworthy difference from the other Seorpiurus spp. described 
above. The root is tetrarch as in S. vermiculatus, and the transition is high 
as in S. sulcata. 
ONOBRYCHIS CAPUT-GALLI, Lam. 
The hypocotyl is sharply constricted just below the collet, this being 
connected with (? caused by) the pressure of the clasping carpels of the fruit. 
The cotyledons are large, slightly thickened, and clearly asymmetrical, one 
edge being straight, the other curved. Figures are given by De Candolle 
(1825, pl. 14) and Klebs (1885, p. 608). 
The root is triarch, three equal and equidistant xylems surrounding a fair- 
sized pith. This extends to the collet, where changes begin to occur. Just 
above the collet (at the constricted part of the hypocotyl) two of the xylems 
(polar) are seen to be more than 120° apart, the third is becoming V-shaped, 
and a fourth group is appearing opposite the third ; four phloem groups are 
now present, the one originally between the polar xylems having divided. A 
quarter of the way up the hypocotyl the stele is elliptical, the two polar 
xylems are still entire, but the two laterals have divided into pairs of tangential 
groups. Shortly above, the polar xylems also spread out and divide in half ; 
and three-quarters of the way up the hypocotyl four main groups of xylem 
are found, each formed by the fusion of adjoining halves of polar and lateral 
metaxylems. The phloems remain unchanged. Each cotyledon takes two of 
these collateral bundles with the polar protoxylem between. The transition 
thus resembles that found in Scorpiurus suleata in the passage from triarchy to 
tetrarchy, but differs in structural details and in the lower level at which the 
changes occur. 
ORNITHOPUS COMPRESSUS, Linn. 
Hypocotyl tapering gradually to the root. Cotyledons oblong-ovate, shortly 
petioled, slightly secund, pinninerved. 
The root is triarch, with three equal uniseriate xylem plates meeting in the 
centre. The transition is high, a pith not appearing till within about 5 mm. 
of the cotyledonary node. At this level a fourth protoxylem arises on the 
elongated xylem plate in the intercotyledonary plane and almost at once 
divides into halves like the third protoxylem. Thus, while the transition is 
completed on the tetrarch plan the greater part of the hypocotyl is triarch. 
CORONILLA MONTANA, Scop. 
An erect perennial herb. The cotyledons are long-stalked ; the lamina is 
ovate, gradually narrowing to the petiole. 
The root, just below the collet, is triarch ; in the young state two of the 
