Neomeris dumetosa , L amour. 607 
Fig. 3. Rejuvenescence of an old injured axis. The young shoot commencing 
with greatly elongated internodes. 
Fig. 4. Exceptional case of dichotomy of main axis, just above first signs of 
Stage II. 
Fig. 5. Basal portion of plant in Stage I. Branching of the main axis below the 
lowest whorl of scars, (a) possibly young branch developing from a creeping 
rooting portion. 
Fig. 6. Root-portion of healthy plant. Starch-storage general in the lobes. 
Fig. 7. Basal segment of Stage I, showing 2 apical scars. 
Fig. 8. Anomalous branching of main axis in Stage I. 
Fig. 9. Young plants (Stage I), natural size. 
Fig. 10. Commencement of Stage II. ( a ) formation of the septum, delimiting 
the basal portion ; (b) reversion to Stage I. 
Fig. 11. Young plant in Stage II, the upper 10 whorls. In the water the 
lateral members stand out horizontally, they are shown closed in a pencil to give 
the symmetrical effect. 
Fig. 12. Transition to Stage III. 
Fig. 13. Segments of the primary cortex, wearing off on older part of thallus. 
Fig. 14. The primary cortex of Stage III after loss of the filamentous portion of 
the appendages. 
Fig. 15. Apex of a young plant in Stage III. Cleared in Eau de Javelle to 
restore normal turgidity. Formation of cortex at fourth and fifth node behind 
the apex. 
Fig. 16. Longitudinal section of Stage III, cortical segments enclosing a cavity. 
PLATE XXII. 
Figs. 17, 21, 22, 24, 25, 26, Zeiss 3 A. and reduced f. 
Figs. 18, 19, 20, 27, Zeiss 3 D. and reduced •§. 
Figs. 28, 29, x 5. 
Fig. 17. Upper portion of plant passing into Stage IV after formation of 42 
whorls of Stage III. Reversion after 4 whorls and back again after 3. 
Fig. 18. Section of apex showing transition, after 36 whorls of Stage III. 
Cortical layer in continuity at the ninth node from the apex. Stage IV laid down 
at the third node from the apex. 
Fig. 19. Characteristic basal segment of Stage IV, showing 2 apical scars. 
Fig. 20. Portion of main axis near the base. Transverse elongation of scars, the 
cellulose plug retains its circular contour. Number of members in a whorl at this 
point, 14-16. 
Fig. 21. Transverse section of plant in Stage IV, partly decalcified. The depth 
of shading indicates the amount of deposit, as seen by transmitted light. Number 
of members in a whorl, 18-20. 
Fig. 22. Older portion of thallus at transition from Stage III to IV, showing 
irregularities in formation, and scanty remains of whorls of members. 
Fig. 23. Full type of ‘leaf’ in Neomeris dumetosa , showing specialization of 
basal portion and addition of new outgrowth, the aplanosporangium, at the first 
bifurcation. 
Fig. 24. Transverse section of adult plant at about the middle of its calcified 
