the Genus Hottonia . 
257 
endodermis, but the pericycle is represented by a ring of lignified fibres 
( pc .) — a family likeness to the Primulaceae (Solereder (10), p. 504). 
At the node the lacunae and fibres disappear, the bundles fuse, and 
a starch sheath forms externally (Fig. 13) around the vascular ring, and 
occasionally also internally to it (Fig. 14). A gap is left where the pedicel 
trace leaves the stele (br. gp ., Fig. 13), which is usually closed before the 
bundles separate. The leaf-gap does not occur in the central stele, but in 
the branch trace, as the procambial strand of the bud always unites with 
the trace of its subtending leaf at the extreme distal point of the latter, i. e. 
Text-fig. 2. Part of a transverse section across the subterranean part of the rhizome. ( x 240.) 
just before it runs out into the leaf (cf. Text-fig. 4), as Gwynne-Vaughan (5), 
p. 314, describes for several species of Primula. Hence, when the bud 
develops into a branch, the leaf-trace is entirely fused with the vascular 
strand of the latter in its passage through the cortex, and is even occasionally 
carried up a slight distance into the branch itself, before passing out into 
the leaf — a link with Samolus. 
At the base of the inflorescence the bundles again fuse into a more or 
less complete ring, which is almost immediately interrupted by the large 
branch gaps. At about this level, the starch sheath begins to show the 
characteristic endodermal thickening, and extends round the margins of 
the gaps, becoming connected with the cells internal to the protoxylem, 
which are seen to be irregularly but strongly lignified. The stele thus 
becomes broken up into several distinct band-shaped pieces, each of which 
s 
