Notes. 
I 7 I 
the endodermis. The leaf-trace is supplied with a large arc of xylem 
which separates off from the stele, leaving a gap in it which affects 
the whole of the vascular ring, endodermis, phloem, and xylem; so 
that the parenchyma in the centre of the stele becomes continuous 
with’ that of the cortex. Passing towards the apex of the stem the 
xylem ring sopn becomes complete again, and shortly afterwards so 
does the (external) endodermis, but the phloem ring remains for a 
C 
Fig. 19. 
considerable time interrupted by a ridge or strand of parenchyma 
continuous with that which forms the leaf-gap, lying on the outside 
of the xylem ring, and eventually covered in externally by the endo- 
dermis. The strand consists of cells similar to those of the pith, and 
easily distinguished from the elements of the phloem by their greater 
size, rounded outline, and dense starchy contents. 
