XIV ILLUSTRATIONS IN THE TEXT. 



FIGS. PAGE 



14. Enlarged node of underground stem of Char a 



delicatula (after Kuczewski) . . . .41 



15. Symmetrical star-like stein-bulbils of Nitellopsis 

 obtusa (after Giesenhagen, H. Groves and 

 Migula) ........ 42 



16. Position of the reproductive organs in the four 



genera (after Sachs, Braun and Migula) . . 44 



17. Position of the reproductive organs in Chara 



fragilis (after Strasburger) . . . .45 



18. Development of the antheridium of Nitella flexilis 



(after Sachs) ....... 47 



19. Mature antheridium (after Prosper) . . .48 

 20. Development of the antherozoids (after Guignard) 49 



21. Development of the oogonium of Chara vulgar is 



(after De Bary and Migula) . . . .51 



22. Development of oogonium of Nitella flexilis (after 



Sachs) ........ 52 



23. Process of fertilization (after De Bary) . . .54 



24. Fully developed oogonium (after Migula and 



De Bary) ...... .55 



25. Terminal disposition of ridges of oospore 58 



