388 West,— A Contribution to the Study of the Marattiaceae. 
the leaf-trace. No gaps other than leaf-gaps occur in the external vascular 
cylinder. 
The double leaf-traces, which are arranged in a fairly regular spiral, 1 
leave the outer cylinder from near the base of the leaf-gaps and at first 
pass out to their respective leaves so gradually, branching meanwhile in 
the cortical ground-tissue (Text-figs. 1 7 and 18), that the traces of a number 
of leaves appear in a transverse section of the stem and present an appear- 
n.s. 
Text-fig. 17. Marattia Cooperi , Mre. Model of the stelar system of the caudex of an adult 
plant, viewed from one side, c.s., commissural strand ; l.t., leaf-trace ; r.t., root-trace. 
ance very similar to that of the outermost ring of bundles of the stem-stele 
in Danaea , with which at first sight they may very easily be confused. 
However, the model clearly demonstrates their true foliar nature ; anasto- 
mosings between adjacent leaf-traces never take place. 
Usually a root- trace fuses with the main vascular cylinder just below 
the point of departure of the leaf-trace (Text-fig. 17), and there is generally 
one root to each leaf, as Holle (34) pointed out long ago. Other root-traces 
join the central stelar system at irregular intervals (Text-figs. 17 and 18). 
No third cylinder was developed in the specimen examined. It 
1 The leaf-divergence = 144 0 approximately. 
