THE OLDER SPOROPHYTE 



189 



fussia or Dancea. It was not quite certain whether a single apical cell was present 

 at this stage, but a triangular cell which could be seen at the apex was probably 

 the apical cell of the young leaf. The root apex of this specimen had been injured 

 so that the form of the apical cell could not be clearly made out, but it was probably 

 the same as we have already described for the young sporophyte. The apical cell of 

 the stem meristem was broader in outline than that of Dancea and truncate below. 

 The vascular system at this stage, as we have already indicated earlier, consists 

 of the common bundle of the root and the cotyledon, which is joined at a point quite 

 close to the stem apex by the second leaf trace. The first tracheary tissue is visible 

 at this point in the form of short, reticulately marked tracheids such as we have 

 already seen in the young sporophyte of Dancea. At this stage no mucilage ducts 

 or tannin cells had developed. About the base of the young leaves are short hairs 



Fig. 172. 



A, B. Two longitudinal sections of a young 

 sporophyte of Marattia douglasii. /^, 

 second leaf; »-^, second root. X140. 



C. Part of primary root, showing cells in- 

 fected by endophytic fungus. 



Fig. 173. 



Section of a young sporophyte of Marattia 

 douglasii. si, stem apex; /, young leaves; 

 /■, roots. X 25. 



and scales like those we have seen in the other genera. They are more like those of 

 Kaulfussia than like the peltate scales found in Dancea. 



Sections of a somewhat older sporophyte are shown in figure 172, this section 

 being made at right angles to the one just described. The cotyledon in this specimen 

 was fully expanded and the primary root had penetrated into the earth. The 

 arrangement of the bundles was the same as in the younger sporophyte described, 

 except that the third leaf was now visible and the second root was already well 

 advanced. The section passed exactly through this root, the stele of which is seen 

 to join that of the second leaf and is practically continuous with it. The young 

 trace from the third leaf joins the second leaf trace near its junction with the second 

 root. The apical cell of the latter was readily seen and appears in longitudinal 

 section of nearly triangular form, but with the base somewhat truncate (fig. 177, C). 



The tracheary tissue in the middle of the sporophyte is pretty well advanced 

 and the formation of the tracheary tissue has extended for some distance into the 

 primary root and the cotyledon. In the former a single elongated tannin sac could 



