I'RESIDEI^JTIAL AUbKESS — SECTlUA C. 73 



native vegetation may be a valuable guide to the character of 

 the soil irom an agricultural and hortictiltural point of view. 

 My old Professor of Agriculture, the late Professor Hilgard, 

 was, I think, one of the hrst to apply this concept to agricultural 

 practice, and I was engaged with hnii for some time in carrying 

 out investigations on the relation of the vegetation to the alkali 

 soils of California. The relation between a soil and its type 

 of vegetation is especially marked in the case of brak soils, and 

 this fact f tirnishes a valuable warning to the prospective settler as 

 to soils to be avoided. On the South African High \'eld the 

 character of the grass becomes a guide to the character of the 

 pasturage as regards ' 'sweetness," which, again, in some dis- 

 tricts at least, appears to depend on the character of the soil. 



In certain parts of the country the presence of subterranean 

 springs is indicated by the growth of a different type of vegeta- 

 tion ; these moisture-indicators differ in different phytoger)gra[)hi- 

 cal regions. Where the Vaal-bosch ( Tarchoiiaiitlnts ) is a domin- 

 ant feature of the vegetation, we may expect to find lime near 

 the surface, sometimes in the form of a hardpan which renders 

 the soil tmsuitable for agriculture. Where the wild Seringa 

 {Burkea africana) occurs, we learn to look for the Gift-blaar, 

 Dichapetalum cymosum, so deadly to live-stock grazing in the 

 springtime. Grass-veld, the vegetation of which contains a con- 

 siderable admixture of plants other than GraminCcX, whether 

 they be Cyperaceae or Dicotyledoneae, not only does not furnish 

 so much grass as the typical grass-veld, but that which is 

 present is often much less nutritious ; it may be a paradise for 

 the botanist seeking for species, but to the grazier it is " sour." 

 Clay soils, black turfs, sandy soils, and (|uartzite and con- 

 glomerate soils each produce more or less distinctive types of 

 vegetation which future investigation may prove to have value 

 as soil indicators, especially where reconnaissances are being 

 made for the selection of ranching country, or country suitable 

 for closer settlement. In this connection it is well to note that 

 appearances are often deceptive, and that the most densely 

 grassed cotmtry dt)es not necessarily afford the best or mijst 

 nutritious grazing. 



Rainfall. — So also with regard to rainfall. We know well 

 how the succulent vegetation of the true Karroo differs from 

 that of the Composite-Karroo, and that, again, from tlie fl<^ra 

 of the Grass-Steppe. But even in the Grass-veld of the high 

 plateau, we find a marked difference between the vegetation of 

 the ]\Iachadodorp-\'olksrust Zone with a rainfall of al)out 33 

 inches, and that oi the Middelburg-V'ereeniging Zone, with 

 approximately 2~ inches ; the flora of this beU differs, again, 

 from that of the belt Iving west of Klerksdorp with 18 to 20 

 inches, while — going still farther west of the Kimberley-Mafe- 

 king railway — we get a different type again before we reach 

 the true Kalahari. We know that the rainfall diminishes as we 

 proceed westward from the Drakensberg (excepting perhaps on 

 the high ridge of the Witwatersrand ), forming rainfall belts 



