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DR JOHN M : LEAN THOMPSON ON THE 
in the phloem is more marked than in the xylem, and in the parenchyma which 
fills the gap in the latter there are a few small isolated tracheides. Neither the 
pericycle nor endodermis appear in any way disturbed. There is thus established 
a potential perforation of the leaf-trace. 
Text-fig. 8, 
As the trace is followed outwards the continuity of xylem and phloem are 
consecutively re-established in the leaf-base, the abaxial xylem is thickened, and 
there is no sign of the potential break seen in the basal portion of the trace. In 
the petiole the leaf-trace is enlarged, and in transverse section appears as a wide 
fl (text-fig. 9). There are apparently four protoxylem groups ( p .), and the phloem 
— which is hatched in the figure — completely clothes the abaxial face of the xylem, 
and is continued adaxially around the xylem margins. In the rachis the trace is 
