in Rhodymeniales : II. Deles seriaceae. 201 
Fig. 12. A single procarp (unfertilized) showing the relation of the sterile 
filaments (red) to the carpogonial branch, x 900. 
Fig. 13. A single procarp at a stage subsequent to fertilization. The carpogonial 
branch is still present but by no means so conspicuous relatively as in the figure. 
The auxiliary cell has been cut off from the anterior part of the pericentral cell. 
The sterile filaments begin to undergo mucilaginous degeneration, x 500. 
Fig. 14. Median vertical section of a segment about the stage shown in Fig. 7. 
The carpogonial branch is still visible, but only with difficulty traceable in a 
section. The auxiliary cell has developed a minute tuft of gonimoblast-filaments. 
The section is drawn through the carpostome, and the invaginated portion of the 
external surface is shown below, x 300. 
Fig. 15. A strong gonimoblast-filament giving rise to an apparently adventitious 
lateral branch, x 300. 
Fig. 16. Lateral view of the apical region of a procarp-bearing segment. 
Magnification inferior to that of Fig. 11. x 350. 
PLATE XVI. 
Delesseria alata , Lamx. Figs. 17, 18, 19. 
Fig. 17. Vertical section through a procarp-bearing segment close behind the 
apex. The pair of procarps corresponding to every axial cell is shown. The first 
and third pair of carpogonial branches are on the hither side of their pericentral 
cells, and the second on the farther side, x 600. 
Fig. 18. A fertilized procarp in vertical section. The auxiliary cell has already 
divided once. The carpogonial branch is not shown, x 400. 
Fig. 19. A stage later. The auxiliary has given rise to a tuft of filaments by 
repeated branching, x 400. 
Delesseria ruscifolia , Lamx. Fig. 20. 
Fig. 20. Surface view of a fertilized procarp. The cells hatched by horizontal 
lines are three cells of the axial row and two lateral pericentral cells. These five 
cells stain readily. The carpogonial branch is distinctly visible. The pericentral 
cell has divided off (anteriorly) an auxiliary cell. The sterile derivatives of the 
pericentral cell coloured red. The other cells are superficial, x 750. 
Delesseria Hypoglossum , Lamx. Figs. 21, 22, 23. 
Fig. 21. Two cells of the axial row close to the apex with its derivative peri- 
central cells. From each of these are derived sterile derivatives and a carpogonial 
branch, x 1 200. 
Fig. 22. Three axial cells far behind the apex. The carpogonial branches 
immersed in the tissue of the midrib and atrophying, x 300. 
Fig. 23. A view from the surface, corresponding to that shown in Fig. 20, for 
D. ruscifolia . The auxiliary has grown out into gonimoblast-filaments. The 
sterile cells are omitted, x 750. 
• Nitophyllum laceratum , Grev. Figs. 24, 25. 
Fig. 24. Vertical section of the thallus, showing a pair of carpogonial branches, 
arising from the pericentral cells of one axial cell, x 75°* 
Fig. 25. Surface view of a procarp. The axial cell is not shown, x 75 °* 
