THE OLDER SPOROPHYTE 



185 



The young sporophyte of Kaulfussi a is almost completely destitute of the tannin 

 cells which are so conspicuous a feature in Dancea, and these tannin cells are prac- 

 tically entirely absent from the sporophyte throughout its whole existence. In this 

 respect there is a marked resemblance to Ophioglossum. The mucilage ducts are 

 also somewhat less developed than in the other Marattiacese and are mainly con- 

 fined to the central part of the stem in proximity to the vascular bundles. At a late 

 period they may also appear in the cortical region. Their lysigenous origin is less 

 evident than in Dancea and it is not impossible that they may sometimes be of 

 schizogenous origin, as Brebner states is often the case in Dancea. 



The structure of the vascular strands is very much like that of Dancea, as a 

 reference to the figures will show. There are developed slender, spirally-marked 

 protoxylem elements like those in Dancea and which we have already seen occur 

 also among the Ophioglossaceae, in Helmtnthostachys. 



The stipules in the young plants o( Kaulfussia are much less definite than they 

 are in Dancea. A cross-section through the bases of the young leaves shows that 

 instead of the bases appearing free, each with its distinct stipules, the leaf is confluent 

 with the next one, one side being slightly extended and free. The leaf base thus 

 incloses the next younger leaf completely on one side, but leaves it free on the 



Fig. 169. 



A. Bundle from intermediate region of a very young sporophyte of Kaulfussia. X150. 



B. Section of primary root. X150. 



C. Section of bundle of second root, en, endodermis. X150. 



Other (fig. 168, 5). In the later leaves the stipules become more conspicuous, but 

 they are always connected by a very conspicuous commissure in front (fig. 171, coni) 

 so that a section of the young leaf base shows a space between the front of the petiole 

 and the stipular sheath. In short, the structure is very similar to the open stipular 

 sheath of Botrychium virginianum and apparently arises in much the same way. 



The structure of the adult sporophyte has been carefully investigated by Kiihn, 

 who pointed out that it is the simplest of the Marattiaceae in the structure of the 

 stem (fig. lyi, B). As in the young sporophyte, the stem shows in section a single 

 circle of vascular bundles, but there is in addition a single median strand within the 

 circle of bundles belonging to the dictyostele, and this bundle is presumably of 

 cauline origin, like the corresponding one in Dancea. 



The whole vascular skeleton of the stem, when removed by maceration, was 

 found by Kiihn to be a hollow cylinder with large open meshes. These are more 

 elongated on the ventral side and from these ventral strands alone, according to 

 Kiihn, the roots are developed. In this respect Kaulfussia offsets a certain analogy 

 to Helmtnthostachys and perhaps to Ophioglossum pendulum. 



As in the other Marattiaceae, the ground tissue of the rhizome is composed of 

 simple parenchyma. The outer layers have their walls brown in color and show the 

 reaction of cork. Except for the presence of the central strand, a section of the 



