620 Worsdell. — Anatomy of Stem of Macrozamia. 
Fig. 4. Transverse section of a portion of the periphery of the pith where 
a medullary bundle is in the ect of passing out through the normal ring. X30. 
Fig. 5. An involuted portion of a medullary bundle. X30. 
Fig. 6-8. Transverse sections of incipient stages in the development of medullary 
bundles. Figs. 6 and 8, x 85 ; Fig. 7, x 45. For Fig. 8 see PI. XXVIII. 
Fig. 9. Transverse section of the region between the normal and the first 
anomalous ring, showing a small bundle with inverted orientation. X45. 
Fig. 10. Transverse section of a segment of the second anomalous ring, with 
a small inverted bundle on its inner side ; ‘ transfusion-tracheides’ between the two 
bundles. Slightly diagrammatic, x 30. 
Fig. 11. Diagram of the normal and the first anomalous zone in longitudinal 
section, showing the oblique connexions between the two. 
Fig. 12. Longitudinal section passing through the extreme outer limit of the 
normal zone and the extreme inner limit of the first anomalous zone, showing 
‘ transfusion-tracheides’ between the two. 
Fig. 13. Diagram of a tangential section of part of the xylem showing the 
local curved course of the tracheides owing to the expansion of the medullary rays. 
The leaf-traces in their outward course are seen in transverse section. 
Fig. 14. Transverse section of a girdle leaf-trace during its tangential course 
through the cortex, x 60. 
Fig. 15. Longitudinal section of the same. X45. 
Fig. 16. Diagram to illustrate the direct radial course of some of the leaf-trace 
bundles through the cortex. For this figure see PI. XXVII. 
Fig. 17. Section through an outermost portion of the cortex, showing the 
mode in which a new periderm-layer arises within the phelloderm of the old 
one. x 30. 
