285 



Fig. 285. Bryothamnion Seaforihii 



(Turn.) Kutz. Part of the thallus. 



(About 4:1). 



fellosen generischen Zusammen- 

 horigkeit mit B. triangulare ange- 

 nommen werden muss, dass die 

 schwach entwickelten Blatter von 

 B. triangulare hier grosstentheils 

 ganz abortirt sind. Haufig abortiren 

 tibrigens selbst die Blatter an den 

 erloschenden Spross-Spitzen mehr 

 oder weniger." This has not been 

 altogether confirmed by the ex- 

 amination of my material. 



The figure 284 shows the 

 growing summit removed from the 

 surrounding protecting branchlets. 

 From this it is evident that the 

 growth of Bryothamnion Seaforthii 

 takes place in a very similar way to that of Bryothamnion tri- 

 quetrum. As in this species, trichoblasts issue from every second 

 segment; the trichoblasts are once forked, each of the filaments 

 consisting of 4 cells, and are upon the whole much like those 

 found in Br. triquetrum; the only difference seems to be that the 

 cells are much shorter. On the other hand their diameter is 

 somewhat longer, about 20 i>.\ sometimes one of the filaments 

 bears a short sidebranch. But while in Bryothamnion triquetrum 

 the trichoblasts are placed in a screw line round the summit with 

 a divergency of 120, in the present species they are placed di- 

 stichously with a divergency of 180. From the basal cells of 

 each of the trichoblasts an axillary branch issues. These branches 

 grow quickly and are bent inwards over the young summit. I can 



not say how far the 

 trichoblasts are placed 

 exactly with a diver- 

 gency of 180 or some 

 smaller variations are to 

 be found ; in every case 

 some small oscillations 

 seem to be present as 

 the branches alternately 

 place their summits over 



f ,z,--/rr v-t. or under the following 

 Fig. 286. Bryothamnion Seaforthii (Turn.) Kutz. 



Transverse section of the thallus. (About 30 : 1). branch. 



