"62 MR. R. H. COMPTON: AN INVESTIGATION OF THE 
This condition lasts to within a few millimetres of the cotyledonary node, 
but the amount of xylem diminishes slowly. 
The lateral pairs of. xylem strands become more widely separated, and a 
Fusion is effected between adjoining polar and lateral bundles; the cotyledon 
trace consists of a pair of large collateral bundles, the xylem being composed 
of a great number of scattered spiral vessels ; each bundle being formed by 
the union of a half-polar and a half-lateral xylem group, with sometimes one 
гог more intercalary bundles. 
The bundles supplying each primordial leaf are two in number below the 
node, being attached to the edges of the cotyledon traces ; they gradually 
Approach one another, and finally fuse in the intercotyledonary plane. 
The bundle thus formed is the midrib of the primordial leaf ; it long shows 
indieation of its double origin (fig. 109), Four other large bundles and 
віх small ones are also found in the first epicotyledonary internode. 
The rapid development of secondary tissues near the collet is very striking 
in this species and in other Phaseoles, though it is found to some extent in 
many seedlings ; it is clearly correlated with the early development of an 
‘extensive and much-branched root-system in the collet region. The main 
plumular bundles are early brought into relation with this system, and the 
‘collet xylem ring may be regarded as the main distributing centre of the 
young plant. Its development seems to be precocious so far as the aerial 
‘parts are concerned ; and it may be regarded as dependent on the rapid 
early growth of the root-system, and as anticipatory of the relatively faster 
-epicotyledonary development to follow. 
‘CANAVALIA ENSIFORMIS, DC. 
' C. GLADIATA, DC. 
Two species which only differ, in the stages observed, in the former having 
са red, the latter a white, testa. Large twining biennial or perennial herbs. 
The large hypocotyl narrows abruptly at the collet and bears a considerable 
tuft of lateral roots. The cotyledons are large and fleshy, ovate, green, 
The epicotyl bears the usual pair of primordial leaves with interpetiolar fused 
stipules. 
Much of the structure resembles that of the large Phaseolus spp., 
e.g. Р. Hernandesiz. There are certain differences, however, which must 
“be mentioned. 
The root contains a pith far below the collet, there being four radiating 
biseriate protoxylems, each with a pair of tangential metaxylem wings which 
‘unite to form a complete ring. There are no tannin-sacs in any part of the 
seedling, this being a striking difference from other Phaseolew. For the 
rest the description of Phaseolus Hernandesii wil apply equally well to 
-these species. 
