.95 



1. Intkoduced Grasses. 



(a) Annuals. Anthistiria ciliata, Aira caryophyllea, 

 Koeleria phleoides, Trisetum immihiori, Avena sativa, A. 

 sterilis, A. fatua, A. barbata, Lagurus ovatus, Eragrostis 

 major, Phalaris minor, Lamarckia mirea, Cynosurus echinatus, 

 Briza maxima, B. minor, Poa annua, Scleropoa rigida, Vulpia 

 myurus, V. bromoides, Brornits molliformis, B. arvensis, B. 

 commutatus, B. maximmn, B. unioloides, Brachypodium 

 distachyum, Lolium temulentum, L. multiflorum, L. rigidum 

 var. rottboellioides, Hordeum murinum. 



(b) Perennials : Paspalmn digitaria, Holcus lanatus, 

 Agrostis veriicillata, Dactylis glomerata. 



2. South African Species (one or two of them are doubtfully 



native and ought possibly to have been included above). 



(a) Annuals : Digitaria sanguinalis, Panicuon crusgalli, 

 Setaria vertic.illata, Holcus setiger, Eragrostis aspera, Eleusine 

 indica, Bromus paMilus. 



(b) Perennials : Paspalum scrobiculatiiTn, Sporoholus 

 indicus, Eragrostis curvula, E. hrizoides, Chloris petraea, 

 Ehrharta erecta, E. calycina. 



The results of man's interference are seen most obviously 

 in the various places where the above species are common, as 

 in cultivated land, along roadsides, etc. The various sub-seres 

 progress more or less quickly towards the climax type. The 

 influence of man is also shown, however, in a more general 

 way through the agency of fire and through pastoral opera- 

 tions. Goat grazing often has a profound effect on the vegeta- 

 tion. Ostriches do not eat grass, and grasses therefore tend 

 to increase over ostrich farms. Through such influences, 

 especially that of fire, the natural climax vegetation over great 

 areas tends to give way to other types which must be looked 

 upon as initial stages in a new succession (Sub-sere), but which 

 have a certain degree of stability, and remain in possession 

 for long periods, chiefly because the factors that brought them 

 about (grazing, burning, etc.) prevent the new succession from 

 proceeding any further. W. G. Smith has called such types 

 "Substituted types," and, in previous papers I have written 

 about them under the name of "Charged Veld." In the South- 

 Western region, the species which is usually dominant over 

 great areas of this kind is the Rhenoster bosch, a composite 

 (Elytropappvs r/iinoce;'(9<w), but certain grasses are also impor- 



