i 9 2o] 1IAUPT—F0SS0MBR0NIA 330 



6. Humphrey, H. B., The development of Fossombronia longiseta Aust. Ann. 

 Botany 20:83-108. 1906. 



7. Leitgeb, H., Untersuchungen iiber die Lebermoose, vol. 3, Die frondosen 

 Jungermannien. Leipzig. 1877. 



8. Schiffner, V., Hepaticae in Engler and Prantl's Naturlichen Pflanzen- 

 familien. 1 3 : 38-61. 1909. 



EXPLANATION OF PLATES XVI-XIX 



PLATE XVI 



Fig. 2. — Thallus: a, side view; b, dorsal view. 



Fig. 3 

 Fig. 4 

 Fig. 5 

 Fig. 6 

 Fig. 7 

 Fig. 8 



— Mitosis in apical cell; X1850. 



— Median longitudinal section of apical cell; X660. 



— Median transverse section of same; X660. 



— Rhizoids; X85. 



— Median longitudinal section of thallus through apical cell; X250. 



— Same as fig. 7: a, young antheridium; //, leaf; X68. 



PLATE XV 11 



Figs. 9-20. — Stages in development of antheridium. 



Fig. 9. — Antheridium initial; X790. 



Fig. 10. — Young antheridium consisting of basal cell, stalk cell, and 

 primary antheridial cell; X790. 



Fig. 11. — Vertical division of primary antheridial cell and later vertical 

 division of stalk cell; X790. 



Fig. 12. — Appearance of transverse wall in stalk cell; X790. 



Figs. 13-14. — Formation of periclinal walls in primary antheridial cell; 



X790. 



Fig. 15. — Cross-section of same; X790. 



Figs. 16-17. — Division of primary wall cells; X790. 



Fig. 18. — Division of primary spermatogenous cells; X790. 



Figs. 19-20. — Older stages; X660. 



Fig. 21. — Archegonium initial and apical cell; X625. 



Fig. 22. — First division of archegonium initial, apical cell, and mucilage 

 hair; X625. 



Figs. 23-33. — Stages in development of archegonium. 



Fig. 23. — Archegonium initial; X790. 



PLATE XV III 



Fig. 24. — First division of same; X790. 

 Fig. 25. — Formation of first vertical wall; X790. 



Fig. 26. — Appearance of second and third vertical walls and transverse 

 division of basal cell; X790. 



