On Azolla and Salvinia. 269 



tended to shew that there are more membranes deve- 

 loped in the crowning grume than there are subse- 

 quent lobes, there being in this, on one surface, no 

 less than 7. 

 9. (Yellow) sac and capping grume with its condensed 

 points, at a stage intermediate between fig. 6 and 7. 



10. (Yellow) sac alone. 



11. The same, burst on the trilineal-marked surface. 



12. Lower persistent parts of a pair of calyptrate capsules. 



13. Contents of one of the same, as they separate with the 



calyptra. 



14. Calyptra detached. 



15. Contents without the calyptra, to which they adhere 



by the cup-shaped mass of radicello-fibrous tissue at 

 the apex : nucleary membrane (or secondary capsule) 

 removed. 



16. Contents without the calyptra, and without the nu- 



cleary membrane : lobes somewhat displaced. 

 17. 18. (Yellow) sac, and its incrustation removed, shewing the 

 trilineal mark on its vertex. 



19. Part of the incrustation. 



20. One of the lobes, pulled off. 



21. One of the radicular fibres, 550 times. 



22. (Yellow) sac. 



23. The same burst, and emptied of most of its contents. 



PI. xvii. 



(Development of the other hind of capsules and their contents, part copied 

 from Mr. Bauer's drawing.) 



Fig. 1. Young capsule. 



2. Nucleus and basilar protuberances detached. 



3. The same magnified, about 300 times. 



4. Nucleus and basilar protuberances of another more 



developed young capsule. 



5. One of the lowest or least developed protuberances, 



(very young secondary capsule.) 

 G. Another more advanced. 



7. Ditto still more advanced. 



8. Ditto ditto. 



