315 



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 % 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 (LI thick and 60 u. long. 



The second type consists of disti- 

 chously ramified branchlets (Fig. 320). 



Kiii'. 319. Murrayclla periclados 

 (Ag.) Schmitz. Part of cree- 

 ping filament with rhizoids ;ind 

 erect branches. 

 (About 35:1). 



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- 

 garding 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 



Fig. 320. Murrayella periclados (Ag.) Schmitz. Part kind of side-organs 



af a plant with stichidium having several well-deve- C0 nsists of branches 



loped ramuli. 



(About 50:1). with polysiphonous 



