186 



llll MARATTIAI.F.S 



rhizome of Kaulfussia presents almost the exact appearance of a similar section of 

 Ophtogloi sum. 



In a rhizome having a diameter ol about a centimeter twelve bundles showed 

 in a cross-section taken through the internode, one ot these being tin- medullary 

 strand. The section of a petiole of a leaf taken from tin- same plant is shown in 

 fig. 171. C, and tin- structure of tin- section closely resembles that of the rhizome. 

 There were eight bundles arranged in a circle, within which were two medullary 

 strands. The cortical region was composed of several rows of brownish cells, prob- 

 ably similar to those in the outer part of the rhi/ome, and within these, separated 



Fig. 170. 



Centra] bundle from .1 young sporophyte of Kaul- 

 fussia, showing two xylems. Xico. 



Fig. 171. 



A. kin. oi a large sporophyte of Kaulfussia. u, stip- 



ules; com, commissure. X;,. 



B. Section of rhizome. Xz. 



I . Set ti"n of petiole. X2. 



from them by three or four rows of cells, was a conspicuous band of collenchyma, 

 a tissue characteristic of the leaves of most of the Marattiaceae. 



According to Kiihn, the bundles of the leaves are continued separately into the 

 cortex of the stem ami do not unite into a sin<dc leaf trace. There are occasional 

 anastomoses of the vascular bundles of the petiole, quite like those in the stem itself, 

 and this becomes especially marked at the base of the leaf, so that the leaf trace (if 

 such it can hi- called) forms a hollow reticulate cone, quite equaling in diameter the 

 vascular cylinder of the stem itself, and attached to this by the open base, the sepa- 

 i.ite strands forming a crescent-shaped group when seen in section. The arrange- 

 ment of the bundles within the petiole itself and their method of junction with the 

 vascular system of the- rhizome are very much like those in Ophioglossum pendulum. 

 The vascular bundles, both in the petiole and rhi/ome, are concentric. The 

 endodermis is not recognizable and the central xylem is completely inclosed by the 

 phloem, siev< tubes being developed throughout. 



