55-1- J. W. BEW8. 



mate association or what I have called a '" consortium " (of. Fritsch in 

 • New Phytologist.'1906,p.l58). As far as I can make ont the Gloeocapsa 

 sanguinea has been the first arrival, the two species of Stigonema 

 developing upon this early growth. In the pi'esent material a good deal 

 of the Gloeocapsa looks moribund, although a considerable number 

 of fresh and vigorous colonies are to be found among the tangles of 

 Stigonema. Of the two species of Stigonema, S. hormoides- 

 Bornet et Flahault forma has the upper hand and is more abundant. 

 S. informe Kvtz. forma is suffering largely from the growth of 

 Schi/otlirix epiphytic n. sp. This, which would appear to be the 

 most recent arrival, has in many places almost completely enshrouded 

 thi-eads of the Stigonema with its red coiling filaments. Between 

 the upright branches of S. informe and the Schizothrix a struggle 

 for supremacy is going on. analogous to that described by me on p. 54(V 

 in my paper in the ' Geographical Journal." ' 



If the sequence of forms just oiitlined is coi'rect, it ought to be possible 

 to find patches of the rock just colonised by the Glceocapsa, perhaps- 

 with a thin growth of Stigonema commencing on top. Or a small 

 patch of the rock surface might be laid bare and the succession of 

 growth upon it studied on the spot. 



No. 105 (Tugela Gorge, 7000 ft.). 



A somewhat similar growth to the last, consisting of the same two 

 species of Stigonema; Calothrix parietina (Nueg.) Thtin. var. 

 afrieana nov. var.; Schizothrix muelleri Nueg.. and S. epi- 

 phytica n. sp. ; Glceocapsa sanguinea Kiitz. 



The last mentioned is again in all probability the first form, being 

 followed by the two species of Stigonema and the Calothrix, all 

 three being about equally balanced. Both species of Schizothrix are 

 uncommon and S. epiphyt ica is not nearly as developed as in No. lO^, 

 but it is quite probable that at other points it may attain to the same 

 degree of importance. 



No. 133 (Goodoo Pass. 6000 ft.). 



This is a practically pure growth of Calothrix parietina (Naeg.) 

 Thun. var. afrieana nov. var. It has undoubtenly settled down on a 

 growth of some unicellular member of the Cyanophycese. the remains 

 of which are still visible, but they are not sufiiciently definite to admit 

 of determination. 



The samples dealt with by Dr. Fritsch Avere taken from the 



^ Fritsch, F. E.. *' The Role of Algal Growth in the Colonisation of 

 New Ground and in the Determination of Scenery," ' Geog. Journ.,' 

 November, 1907. 



