Plate 2. 

 Assimilating Thallophytes and Characeae. 



A. Sphaerella lacustris (Girod) Wittr. B. Splachnidium rugosum (L.) Grev. 

 C. Euglena gracilis Klebs. D. Chara stachymorpha Ganterer. E. Enteromorpha 

 intestinalis (L.) Link. F. Navkula spec. G. Codium tomentosum (Huds.) Stackh. 

 H. Staurastrum gracile Ralfs. I. Hydrodictyon reticulatum (L.) Lagerh. K. Gelidium 

 cartilagineum (L.) Gaill. L. Cheilosporum cultratum (Harv.) Aresch. M. Nostoc edule 

 Berk. & Mont. N. Trentepohlia polycarpa Nees & Mont. 



Systematic Table. 



Main division 



Schizophyceae 



(Cyanophyceae) 

 Blue-green Algae 



Family 



Nostocaceae 



from 



Flagellatae 



Zygophyceae 

 Class Bacillariales 

 Class Conjugatae 



Euglenaceae C. 



Diatomaceae 

 Desmidiaceae 



M. Nostoc edule. 



i. Colonies on rock 

 Victoria Falls. 



2. Section of colony showing 



the threads of Nostoc em- 

 bedded in the jelly. 70/1 



3. One thread with heterocyst. 



800/1 

 This species was formerly known 

 only from rivers in Central 

 Asia. 

 Euglena gracilis. 



1. Form with chlorophyll 



granules. 630/1 



2. Form without chromato- 



phores. 630/1 



F. Navkula spec. 500/1 

 H. Staurastrum gracile*. 



1. Front view of plant. 375/1 



2. Two cells in copulation. 



* This alga was obtained from the water pipe of the author's laboratory in 

 Capetown. A filter attached to the water service became suddenly choked and when 

 opened was found to contain small pellets of a greenish substance. The microscope 

 showed that these little lumps mainly consisted of desmids, principally Staurastrum gracile. 

 My friend Professor N. Wille of the University of Christiania kindly identified the 

 following species: Desmidiaceae: Staurastrum gracile Ralfs, Euastrum amoenum Gay, 

 Cosmarium bioculatum Breb.; Volvocaceae: Gonium pectorale Muell., Eudorina elegans 

 Ehrb. ; Pleurococcaceae : Scenedesmus quadricauda Breb. 



The little lumps of algae had probably been carried into the water main from 

 the Disa stream on Table Mountain. 



M. 



