Vegetative multiplication in Crotalaria burhia 229 
lowest branches and completely surrounding them. The various 
branches described above we propose to distinguish by the word 
“normal.” 
After a long time the main shoot with the upper branches dies 
back to the point where the ribs surround it, and that portion of the 
main shoot increases in size owing to the ribs getting thicker and 
more prominent than before. Both these phenomena occur later in 
the case of the lower branches also. 
Afterwards small buds appear terminating some of the ribs, earlier 
in the main shoot than in the lower normal branches. These give rise 
to new branches different in origin (as will appear later) from the 
“normal” branches and we propose to call them “reproductive” 
branches. These reproductive branches, which appear ribbed for a 
short distance from the base, give rise to secondary reproductive 
branches below and secondary normal branches above. 
Internal Structure 
A series of transverse sections of the root from the apex to the 
base was prepared and examined. There is a central cylinder in which 
secondary thickening takes place at a very early stage, so much so, 
that it is very difficult to identify the protoxylem in sections pre¬ 
pared only 6 ins. from the apex of the root. The marked feature of 
the secondary thickening is the great thickness of the phloem. On 
examining the sections it was clear that the ribbed appearance of the 
root and portions of the main shoot and branches already described 
was due to the formation of accessory bundles. 
From the sections cut near the apex it was observed that the 
formation of the cork cambium takes place very early, in the cortex 
just outside the endodermis. The cells of the cortex are quite typical 
and differ in form from those of the pericycle in which cork cambium 
next appears, and the endodermis thus disappears. The cells just 
below the cork then become meristematic and the first xylem vessel 
of the accessory bundle appears. Such single xylem vessels appear 
almost simultaneously at five or six points near the periphery (fig. 2). 
It seems clear that they are formed in the pericycle. New xylem 
elements are added to each as well as some phloem, and small bundles 
are thus produced which project radially (fig. 3). Many such accessory 
bundles appear in succession, some of them in approximately radial 
rows. The later formed bundles are always either outside previously 
formed ones or at fresh points on the circumference (figs. 4 a and 4 b). 
Cork formation takes place around the various accessory bundles. 
