and their Mycorhiza . 6 1 1 
20 . Warlich, W. : Beitrage zur Kenntnis der Orchideen-Wurzelpilze. Bot. Zeitung, 188 6, 
pp. 481 and 498. 
21. Weiss, F. E. A Mycorhiza from the Lower Coal Measures. Annals of Botany, xviii, 1904, p. 255* 
22. Williamson, W. C. : On the Organization and Structure of the Fossil Plants from the Coal 
Measures, part v. Phil. Trans., clxiv, 1874, p. 41. 
EXPLANATION OF PLATES XLVI AND XLVIL 
Illustrating Mr. Osborn’s paper on Aniyelon radicans. 
PLATE XLVI. 
Fig. 1. Root surrounded by numerous rootlets, px. = protoxylem ; pd.= periderm ; = bundle 
trace running to main rootlet of a bunch; m.r. «=main rootlet ; m'.-d . = main rootlet of a bunch that 
left root ( r.t .) higher than plane of section; rr. = rootlets, lateral branches of m ,r' . showing the way 
that lateral rootlets branch immediately on leaving the main root. 
Fig. 2. Transverse section of rootlet, x. = diarch xylem ; ph.= phloem; end. = endoderms ; 
i.c.= inner cortex, cells with dark contents; o.c.— outer cortex. 
Fig. 3. Longitudinal section of root apex, rx.— root cap ; m.c. = meristemmatic cells; pb.c.= 
periblem elements; //.£. = pleurome elements; sp.v.= spiral vessel ; fx. = cells with hyphae. 
Fig. 4. Transverse section of tetrarch root showing deep-seated origin of periderm. px. = proto- 
xylem ; x. = xylem ; ph . = phloem and pericycle ; c.c. — cork cambium ; pd, — periderm ; c. = cortex cut 
off by periderm. 
PLATE XLVIL 
All figures drawn with camera lucida in outline. Reichert, 7a. obj., x8 comps, occ. 
reduced §. 
Fig. 5. Part of longitudinal tangential section of a rootlet, showing epidermis (epi.) and outer 
cortex (ox.) with hyphae cut transversely. i.c. = inner cortex with host cells containing hyphae. 
A. 282. 
Fig. 6. Cells of inner cortex in transverse section, just before periderm formation, h.c. = host 
cells; r.b. resting bodies. A. 275. 
Fig. 7. Transverse section of rootlet. Young stage in formation of digestive cells. R. I ji6. 
Fig. 8. Digestive cell in longitudinal section, hyphae disorganizing, a central knot of indigest- 
ible matter is forming. A. 282. 
Fig. 9. Transverse section of cells in inner cortex showing late stages in disorganization of 
digestive cells. A. 282. 
