— 262 — 



stehenden Rhizinen , die aus der oberen stumpfen Kuppe des 

 Sprosses zwischen und neben den Tochtersprossen abzweigen". I 

 think that these organs may also serve to strengthen the plant, just 

 as these and the clamps can help to attach loose fragments of the 

 plant to the bottom again. 



The cell-wall in the older part of the thallus is rather thick, 

 thinner in the younger; it is nicely striated in an irregularly un- 

 dulating way. The cell-plasma contains numerous plate-shaped 

 small chromatophores of irregular polygonal outline with the corners 

 running out into shorter or longer, thin prolongations connected 

 in a reticular way (fig. 1 1 d). In the middle of the chromatophore 



a rather large pyrenoid is 

 present. Underneath the 

 chromatophores we find the 

 numerous nuclei in regular 

 arrangement. 



As in so many related 

 species the contents of the 

 cell are often found contracted 

 to some larger and smaller 

 balls richly filled with chro- 

 matophores and nuclei etc.; 

 we find them figured by K ü t- 

 zing, "Tab. phycol.", vol. VI, 

 tab. 88. How far these balls 

 becoming free are able to 

 produce new plants I cannot 

 tell, but it is very likely. 



Fructiferous cells occurred 

 rather often in my collections. 

 The whole cell is transformed into a sporangium (fig. 12 a) and the 

 zoospores escape through numerous holes formed in the cell wall 

 in exactly the same way as I have described for Siphonocladus 

 tropicus 1 ). Quite in accordance with this species the holes pro- 

 trude a little and have radiating striations. Also the cell plasma 

 with chromatophores and nuclei is contracted to an irregular net- 

 work or to more irregular clumps, from which the zoospores are 



*) Børgesen, F., Contributions à la connaisance du genre Siphonocladus 

 Schmitz. (Oversigt over det kgl. danske Videnskab. Selsk. Forhandl. t905). 



Fig. 12. Emodesmis verticillata (Kütz.). 



o. the upper end of a branch transformed to zoo- 

 sporangium (25:1). b. a single clamp (20:1). e. the 

 top of a branch with small branches, one of these 

 with a rhizoid-like appendix , in the middle the an- 

 nular cicatrix from a branch torn off (8:1). d. branch 

 with a rhizoid-like appendix (8 : 1). 



