295 



While the creeping filaments lack trichoblasts, these are pre- 

 sent in the summit of the erect filaments (Fig. 293). In some 

 specimens taken from exposed places these were abundantly 

 developed, in others taken from sheltered spots they were very 

 scarce, often quite wanting. 



The trichoblasts are developed in the upper end of the bran- 

 ches, and, when they first appear, each segment often bears one. 

 As pointed out by FALKENBERG they are placed with a divergency 



Fig. 292. Lophosiphonia obscura (Ag.) Falkenb. a, basal part of plant; b, 

 part of a basal filament showing scars after rhizoids placed in rows, c, trans- 

 verse section of the thallus. d, summit of a filament, (a, about 30:1; c, 

 about 200:1; b and d, about 450:1.) 



of about Y 4 - The trichoblasts are rather robust with somewhat 

 thick walls; near the base of the trichoblasts the cells are about 

 28^ thick and the walls of the cells about 4/^. Most probably 

 the trichoblasts serve as a protection for the young tips, not only 

 against the strong light, but also against the violence of the 

 waves. 



The erect filaments are more or less branched ; the branches 

 have no connection with the trichoblasts (Fig. 293). The upper- 

 most young summits of the branches are much curved, turning 

 their concave side towards the mother branch. 



The tetrasporangia (Fig. 294) are found in shorter or longer 



