SEEDLING STRUCTURE IN THE LEGUMINO&E. 35 
a V-shaped group. Thus there is an agreement with other members of the 
Trifoliez, in that all the four xylems are cotyledonary ; and the exceptional 
behaviour of the third xylem, according to Gérard, is unconfirmed. It seems 
probable that Gérard regarded this third xylem as continuous with vessels 
which are in older seedlings superposed to it, and which are in direct 
connection with the first-leaf trace. 
MEDICAGO sativa, Linn., was examined by Van Tieghem (1870, p.221), who 
stated (as did Gérard for M. falcata, see p. 34) that the cotyledons take two of 
the xylems of the triarch root, the third xylem entering the first leaf. (This 
statement he also made for Hedysarum coronarium and Onobrychis sativa, in 
both of which the present researches indicate, on the contrary, that all three 
xylems are cotyledonary ; as well as for certain of the Viciew, in which the 
plumular nature of the third root xylem is abundantly confirmed.) Van 
Tieghem also observed that some main roots of M. satira show four vascular 
plates, with more or less complete abortion of the fourth ; this being evidently 
the same phenomenon as observed in M. lupulina, M. falcata, бс. 
MELILotus ARVENSIS, Wallr. (Pls. 1. fig. 2 ; 5. figs. 82-81 ; 6. fig. 85.) 
Н ypocotyl tapers gently into the long primary root. The cotyledons have 
an ovate lamina, jointed at the base to a petiole 1 mm. long. 
The root contains a solid triarch xylem star, with equidistant 1-2-seriate 
protoxylem rays (fig. 82). The phloem contains fibres. This structure 
persists for about 5 mm. above the collet ; then one of the xylems gradually 
dwindles (fig. 83), and eventually disappears about half-way up the hypocotyl ; 
the other two xylems straighten into line, and a solid diarch xylem plate is 
the result (fig. 84). There are, however, four groups of phloem with fibres, 
one of the groups from the root having divided. About 7 mm. below the 
cotyledons a pith first appears, and the xylem separates into two V-shaped 
groups; the metaxylems gradually move outwards (fig. 85); and at the 
node the vascular supply of each cotyledon consists of a tangential row 
of bundles; in the middle the vestigial protoxylem, on either side of 
this a wedge-shaped metaxylem group, and on the extremities of the row 
the phloems. Except for the indication shown by the phloems, there are 
no signs of tetrarchy in this seedling. Triarchy passes to diarchy by the 
disappearance of one of the protoxylems, and the upper part of the hypocotyl 
is constructed on the diarch plan, as in Ononis rotundifolia and Medicago 
turbinata. 
LOTEÆ. 
ANTHYLLIS Danna-Jovis, Linn. 
Small undershrub.  Hypocotyl slowly tapering to the root. Cotyledons 
ovate and leaf-like, without axillary buds 
D 2 
