65 



this way being composed of several stories of coordinate systems 

 of branches (Fig. 49). 



As to the structure of the cells, the wall is rather thick and 



Fig. 49. Siphonocladiis tropicus 

 (Crouan) J. Ag. Habit of plant (3 : 1). 



consists of several layers (Fig, 

 45). The numerous small plate- 

 formed and polygonal chro- 

 matophores (Fig. 50 a) are 

 parietal. They are connected 

 together by means of very 

 fine prolongations from their 

 corners. In nearly all the 

 chromatophores a pyrenoid is present. In the wall plasma we 

 further find the numerous nuclei regularly distributed (Fig. 50 c). 



Fig. 48. Siflionocladus tropicus 

 (Crouan) J.Ag. 

 a, a ramified branch with its mother- 

 cell (marked with *). All the branches 

 are still unicellular with exception of 

 the second to the right from the top. 

 Having treated this with glycerine, it 

 assumed the appearance as shown in 

 fig. h: by plasmolysis the cells have 

 again become roundish. (About 16:1). 



