182 



THE MARATTIALES 



The separated xylems become joined lower down into a single transverse plate, just 

 before the junction of the strand with the trace from tin third leaf (hg. 166, /-/), 

 with which it joins in the same way and is continued downward to the junction with 

 the strand arising from the fusion of the second hat trace with tin- cotyledon. Above 

 the junction of the hist and second leaves, the stile of flu second root, which grows 

 vertically downward, joins the stele formed by the junction ol the three youngest 

 leaf traces. 



Above the junction the section of the bundle is nearly circular in outline, the 

 lar<*e tracheids forming a broken group in the center of the bundle, quite like a 



Fig. [66. 



A-C. Series of trail pte of Kaulfussia, of about i 



D. Stem apei. 

 H-J. Three sections lower clown. 



K. Centr.il vascular cylinder ^t ill lower down. 



that shown in fig. 165. 



corresponding stage in Darteea. Some of tin- cells adjacent to the bundle show the 

 typical thickenings on the radial walls, indicating that the) belong to the endodermis, 

 but the limits of tin endodermis are extremely vague. In this plant two mucilage 

 ducts had developed in tin fourth leaf, one <m each side of tin vascular bundle 

 (fig. 166, B, m). 



The second tout is stouter than the primary one and its bundle is march. I he 

 mycorrhiza present in the first tout could not he detected in the second root, hut 

 possibl) may he developed at a latei stage. All of the roots are provided with root 



