332 



Dansk Botanisk Arkiv, Bd. 3. Nr. 1. 



basal cell, the remaining part of the pericentral cell, is divided into 

 a central and three pericentral cells becoming the basal segment 

 of the branch (Fig, 332 d). In this way the branch is placed upon the 

 middle of a segment and not near the upper walls between the seg- 

 ments as always in the case of the Rhodomelaceæ. 



The growth in length of the filaments takes place with the aid 

 of a rather large conical apical cell (Fig.332 a), from which the lowest 



part is gradually cut 

 off by means of a ho- 

 rizontal wall into flat, 



disc-like segments. 

 These cells are again di- 

 vided by vertical walls 

 into the small central 

 cell and the three peri- 

 central cells. 



Epiphytic upon other 

 algæ, the irregularly 

 ramihed and twisted 

 filaments of Falkenber- 

 gia Hillehrandii forms 

 densely matted tufts 

 up to a height of two 

 to three cm. The rami- 

 fication is very irregular 

 (Fig. 333 A), rather long 

 parts of the filaments 

 often being undivided, 

 whilst in other ones the 

 ramifications occur close together ; large spongy clumps being formed 

 in this way. It is fixed to the host plant by means of irregularly 

 shaped, often disc-like haptera (Fig. 333 F, G) emerging from 

 the lowest, more or less horizontally growing filaments. These as 

 well as the haptera are thick-walled in contrast to the otherwise 

 rather thin walls of the thallus. 



There was not any kind of reproductive organs found in my 

 specimens; Collins has succeeded in finding tetraspores. According 

 to him »they are tripartitely divided and formed from one of the peri- 

 central cells of a ramulus quite as in Polysiphonia, but occurred singly 



Fig. 332. Falkenbergia Hillebrandii (Bornet) Falkb. 



a, summit of a filament, b, part of a raoniliform 



filament, c and d, branching of filaments. 



(About 270:1). 



