278 



(Fig. 277 c). These are about 200 250 // thick, and the cells are 

 nearly quadratic, mostly somewhat shorter than long, about 100 p 

 broad and 85^ long. 



The erect branches are ramified on all sides. The branches grow 

 out to filaments like the mother branch, some of them shorter, 

 some longer. Rhizoids may issue from every cell in the filaments, by 

 means of which they attach themselves to the neighbouring plants 



Fig. 277. Polysiphonia ferulacea Suhr, J. Ag. 



a, base of a plant, b, summit of the same basal filament, c, basal filament 



with erect filament, d, transverse section of a filament. 



(a, about 20:1; b, 250:1; c, 20:1; d, 60:1). 



or other substratum, and when so attached new erect filaments 

 may issue from them. 



The branches are produced without any connection with the 

 trichoblast (Fig. 278 a). The last mentioned are copiously devel- 

 oped and generally quite cover the upper end of the filaments, 

 but they are not very persistent and drop early. A trichoblast is 

 developed upon each segment with a YI divergency. 



The tetrasporangia occur in the summit of the filaments in 

 long rows, a single one in each segment forming together a screw 

 (Fig. 2786). The tetrasporangia are about 60^ thick. 



