PLATE III. 



Fieurp- magnified 500 diameters 



PAGE. 



Fifr. 1. Desmidium cylindriccm, {Didymoprivm Grevilli ,par1 ofaveg- 



etative filament, . . . 25 



" -j. end view of :. cell, . . 25 



" 3. two cells copulated ; chlorophylloae 



contents passing through a gelatin- 

 ous tube, from one cell t" the other, *_'"> 

 : ' |. " Two developed zygospores; the two 



empty cells still connected, . 25 



" Mehotaenium Braunii, D.By. [Palmogkm maarocoeca, K 



a group of three vegetative cells, -11 



FigB. " advancing stages of copulation ami 



spore formation t" the fully developed 

 zygosp .... ''<- 



Pig. 10. \\r~i n \ i \ii m mhi: cum, a group ol seven cells, . 32 



' 11. Mesotaenium EJndijchebianum, a group of four cells, 32 



' 12. Mesotaenium clepSydra, three vegetative cells, . . :'>'-' 



Figs. 13 15, " t"" cells copulating and two de- 



veloped spores, husks remaining 

 attached, .... 33 



16-19. M'lltiM \i;m \ OB8CURA, ..... ''>'' 



li, 17. " " young stage* "I development in gela- 

 tinous enveli ipes. . . 33 



18, 19. '" " more matured forms, . . 33 



I i_ 20. . M'ii:<ii \ i m \ Bryophh v. [S. miuscicola), a group of four, 33 



Figs. 21, 22. Sptrotaeni^ condensata, . .... 33 



