182 BOTANICAL GAZETTE [MARCH 
Fic. 8. Longitudinal section of a more advanced stage illustrating the forma- 
tion of the cavity of the conceptacle. 
IG. 9. Pesca aes section of a young conceptacle some of whose wall cells 
are ie papi he tongue cell contains two nuclei. 
Fic. 10. A aaa of three cells formed from the tongue cell. 
Fic. 11. Young conceptacle showing simultaneous development of wall cells 
and papillae. 
Figures 12-22. Development of the cryptostoma. 
Fic. 12. Initials, longitudinal section; 12a, cross section of the apex; 12m, 
cross section of median portion; 126, cross section of basal portion. 
Fic. 13. Longitudinal section of the two-celled stage. 
Fic. 14. Longitudinal section of the lateral surface of the three-celled stage. 
Fic. 15. Longitudinal section of the interior of the same group of cells repre- 
sented in fig. 14. 
Fic. 16. Longitudinal section showing four wall cells and the tongue cell. 
Fic. 17. Longitudinal section slightly more advanced. 
Fic. 18. Longitudinal section of a young cryptostoma beginning to form 
paraphyses very early. 
Fic. 19. Longitudinal section of an older stage which has not yet begun to 
develop og aa 
Fic i Loaditadinal section showing five paraphyses developing from wall 
cells sia one from the ton e 
Fic. 21. More ‘vaiee illustrating the simultaneous development of 
paraphyses and wall ce 
Fic. 22. Still more iluaspach 
PLATE XI. 
Fig. 23. The development of papillae which will later give rise to spermato- 
sts. 
Fic. 24. At the left a cell which results from the separation of a papilla from 
a wall cell. At the right a spermatocyst and stalk which have been formed by the 
division of a cell similar to the one shown at the left. 
Fic, 25. A stalk cell has given rise to a papilla, now separated by a wall. 
Fic. 26. A branch system formed through the activity of stalk cells. 
Ah Fic. 27. A spermatocyst containing sperms. The stalk cell has developed a 
air. 
Fic. 28. A mature spermatocyst, the stalk cell pushing out at one side. 
Fic. 29. Very young oocyst with its sister cell, which is the homologue of the 
stalk cell in Fucus 
FIG. 30. Slightly older oocyst and its sister cell already unequal in size 
Fic. 31. A mature embedded oocyst containing many hnshatophines and 
much reserve material. 
Fic. 32. A sporeling still attached to the surface of the parent plant. At one 
pole rhizoids have begun to develop. The old wall of the oocyst surrounds the 
sporeling. 
