312 



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



filaments grow downwards in the furrow between the pericentral 

 cells of the main filament (Fig. 314); later on from the other basal 

 pericentral cells in the branchlets similar filaments are issued, form- 

 ing together the cortical layer surrounding the central axis in the 

 main filament. 



As already mentioned the stichidia (Fig. 317) are formed in 

 the upper end of the trichoblasts. The upper end of the central 



axis becomes polysiphonous 

 and a sporangium is developed 

 in each segment. The sporangia 

 are arranged in a spiral line 

 and, as they increase in size 

 proportionately much more 

 than the sterile cells of the 



P'ig. 315. Wrightiella Tumanowiczii 

 (Gatty) Sclimitz. Part of young fila- 

 ment witli trichoblast and spinelike 

 branchlets. 

 (About 90:1). 



Fig. 316. Whrightiella Tumanowiczii 



(Gatty) Schmitz. Tranverse section 



of a mVin stem from the place where 



a spinelike branchlet is issued. 



(About 50:1). 



segments, the whole stichidium becomes screwformed. As in the 

 case of the sterile part so also in the fertile one each segment 

 carries a monosiphonous ramulus. In the fertile part these are often 

 rather short. A short, sterile tip with small ramuli arranged spirally 

 crowns the stichidia. 



The fig. 317 shows a comparatively short stichidium and a longer 

 one; these contain often twenty or even more sporangia. The basal 

 monosiphonous part of the trichoblasts is in all essentials hke that 

 of the sterile trichoblasts; but the cells are slender and, on the other 



