The Anatomy of Matonia sarmentosa, Baker. 307 
xylem appears to he triarch, this statement being all of which the 
material admits. 
Node. 
Tansley (12, p. 196) remarks:— “ The structure of the node 
(of M. sarmentosa ) has not been examined, but there can be little 
doubt that the internal cylinder connects with the outer one either 
directly or by a branch.” In the material which I have studied, 
and in which the central cylinder is haplostelic, the former alternative 
proves to be the true one. The arrangement of the vascular system at 
the node is of a simple type (Fig. 42), recalling the structure found in 
Fig. 42. Diagrams of a series of transverse sections through the rhizome 
at a node. Xylem outlined, protoxylems indicated by a cross, endodermis a 
dotted line. 
immature plants of M. pectinata (Tansley and Lulham, 11, p. 498, E). 
An arc of vascular tissue detaches itself from the upper part of the 
solenostele, one edge becoming free before the other and the leaf- 
trace being tilted over to one side in consequence. When completely 
detached from the solenostele the leaf-trace is of the common 
gutter-shaped type, the comparison being rather with the leaf-traces 
of young plants of M. pectinata than with the adult. The leaf-trace 
consists of a xylem arc, completely invested in sheaths of phloem, 
