464 ' BOTANICAL GAZETTE [june 



sporogenous nucleus; sptn.mx., spermatium mother cell; st.c, stalk cell; 



trichogy 



PLATE XIX 



Fig. 8. — Vertical section through holdfast showing horizontal hypha and 

 vertical ascending, dichotomously branched hyphae; X355. 



Fig. 9. — Slightly diagrammatic; vertical section through base of plant 

 and holdfast ; X 1 70. 



Fig. 10.— Longitudinal section through wall of thallus showing radial 

 hyphae arising as branches of longitudinal, medullary hyphae; X700. 



Fig. ii. — Longitudinal section through apex of young branch; X340. 



Fig. 12. — Surface view of subcortical cell showing structure of chromato- 

 phore; Xiooo. 



Fig. 13. — Longitudinal section through an intercellular connection show- 

 ing granules of which disk is composed ; X 700. 



Fig. 14. — Longitudinal section through an intercellular connection, between 

 2 carpospores, in which granules have not yet become grouped together to form 

 disks; Xiooo. 



Fig. 15. — Transverse section through wall of thallus of male plant showing 

 stalk cells, spermatium mother cells, and spermatia; Xiooo. 



Fig. 16. — Longitudinal section through binucleate spermatium mother 

 cell; X1400. 



Fig. 17. — Similar section; spermatium mother cell which has budded off 

 one spermatium; X 1400. 



Fig. 18. — Transverse section through wall of male plant showing free 

 spermatia imbedded in gelatinous sheath of thallus; Xiooo. 



Fig. 19. — Longitudinal section through spermatium mother cell and sper- 

 matium; chromatophore at base of spermatium mother cell; X1400. 



Fig. 20. — Longitudinal section through wall of thallus showing origin of 

 carpogonial branches; X355. 



Figs. 21, 22. — Longitudinal section of first cell of carpogonial branch, 

 showing mode of origin from subcortical cell; chromatophore is similar to 

 those of vegetative cells; Xiooo. 



Fig. 23. — Longitudinal section of a 2-celled carpogonial branch; Xiooo. 



Fig. 24. — Similar section of a 3-celled carpogonial branch; Xiooo. 



Fig. 25. — Longitudinal section of a 3-celled carpogonial branch; Xiooo. 



Fig. 26. — Similar section of a 4-celled carpogonial branch showing that 

 number of cells is increased by division of terminal cell; Xiooo. 



Fig. 27. — Similar section of a 4-celled carpogonial branch showing that 

 branches at this stage may be bent to form a right angle; Xiooo. 



Fig. 28. — Four-celled carpogonial branch; nucleus in terminal cell contains 

 7 chromosomes ( ?) ; X 1000. 



Fig. 29. — Five-celled carpogonial branch showing position and structure 

 of chromatophores; Xiooo. 





