PLATE X11. 
Fic. 1. Protopteris Witteana, Schenk. Portion of a stem axis showing 
leaf-bases and adventitious roots, etc. Page 73. 
Probably Mantell Coll. 
Fic. 2. The upper surface of Fig. 1 showing the form and arrangement 
of the vascular bundles. P. 73. 
Fia. 3. A single leaf-scar with the characteristic leaf-trace bundle. 
Pave: 
Fic. 4. Small piece of a stem vascular bundle. Magnified 45 times. 
Pie: 
a.= Tissue between leaf-bases. 
b.= Limit of Phloem. 
p.= Portions of the stem vascular bundles passing out 
to the petioles. 
7. = Adventitious roots. 
s. =Sclerenchyma. 
t, = Leaf-trace. 
