EXPLANATIONS AND REFERENCES, 

 PLATE LXXIII. 



PAGE. 

 Fig. 1. OEDOGONIUM, filament of a nannandrous alga, . . .67 



" 2. Transverse striae the result of the process of cell multiplication, 67 



" 3. The same more fully illustrated, . . . .67 



" 4. Filament of female nannandrous alga, ... 67 



" 5. Androsporangia with androspores escaping; oogonium with pore 



superior, ...... 67 



" 6. Filament of female monoecious plant, . . . .67 



" 7. Spermogonia hypogynous, spore spherical, pore superior. . 67 



" 8. Filament of a monoecious form ; 9. gperiiiogonia cells hypogy- 



nous; 10. subhypogynous ; 11. epigynous ; 12. subepigy- 

 nous ; 13. apical. . . . . . .67 



" 14. Pore of oogonium open centrally, .... 67 



" 15. A male plant, . . . . . . .67 



" 16. Androsporangia cells, ..... 67 



" 17. Androspores escaping, . . . . . .67 



" 18-19. Dwarf males, basal supporting cells and spermogonia, or upper 

 cells of the dwarf males which bear the spermatozoids. 

 opening on the top to allow their escape to fertilize the 

 oospore, . . . . . . .67 



" 20. A zoospore making its way out of cell, . . . 67 



" 21-23. Three zoospores fully out of cells, . . . .67 



" 24-26. Zoospores in first stages of development, ... 67 



" 27-30. More advanced stages of growth, . . . .67 



" 31-33. Imperfect zoospores passed out through slit in cell, remaining 



attached, ... ... 67 



" 34. An oogonium and oospore fertilized by a multitude of active 



spermatozoides (?) . . . . . .67 



" 35. An oogonium showing how some are destitute of a pore, but 



open by an operculum or lid, . . . .67 



Figs. 36, 37. An oospore passing out of an oogonium of a vegetative plant, 67 

 " 38, 39. Young developments from oospores, . . . .67 



