West. — A Contribution to the Study of the Marattiaceae . 385 
Text-fig. 16. i-x. Kaulfussia aesculifolia, Bl. These diagrammatic figures illustrate in 
successive, but not consecutive, transverse sections the changes and rearrangements that take place 
in the vascular system of the petiole of an adult plant in the regions indicated on xi. x 6. xi, nat„ 
size. 
meristeles that are about to close a foliar gap. This central strand soon 
separates off again and passes on across the central ground-tissue to the 
next leaf-gap above, which it helps to close up (cf. the young sporophyte 
of Danaea ) ; root-traces arise from the external surface and sides of the 
stem-meristeles, a root-trace invariably arising from the point where the 
