F. Børgesen: Rhodophyceæ of the Danish W. Indies. 



315 



Fig. 319. Murrayella periclados 

 (Ag.; Schmitz. Part of cree- 

 ping filament with rhizoids and 

 erect branches. 

 (About 35:1). 



The plant has four pericentral cells 

 and altogether lacks a cortical layer. 

 It increases by means of an apical cell 

 from which flat disc-formed segments 

 are cut off. From these the side-organs 

 issue spirally with a 34 divergence be- 

 fore the segments are divided. 



As described by Falkenberg the 

 side-organs are of three different types. 

 The most common are- the unbranched, 

 monosiphonous ones (Fig. 318); these 

 occur especially in the basal part of the 

 main filaments and on the whole in the less 

 vigorous filaments. The cells in these are 

 about 28 |u thick and 60 \i long. 



The second type consists of disti- 

 chously ramified branchlets (Fig. 320). 

 The main axis in these branchlets is polysiphonous, while the side- 

 organs are monosiphonous and these occur alternately 

 on both sides of it. 



Between these two kinds of branchlets an even 

 transition is to be found. As pointed out by Falken- 

 berg it may happen that the monosiphonous, 

 not ramified branchlets have a plurisiphonous 

 base and, on the other hand ramified 

 branchlets occur which are monosi- 

 phonous throughout and further, re- 

 gard ing the ram ification of the branch- 

 lets, an even trans- 

 ition is also pre- 

 sent here as bran- 

 chlets with a single 



side-branch are 

 found, others with 

 two or more. 



Finally the third 

 kind of side-organs 

 consists of branches 

 with polysiphonous 



Fig. 320. Murrayella periclados (Ag.) Schmitz. Part 

 af a plant with stichidium having several well-deve- 

 loped ramuli; 

 (About 50:1). 



