36 



f the Eremian or saltbush character; and the difference 

 between the country lying on either side of the line is very 

 marked. Even short distances will clearly demonstrate the 

 limits of the 10-inch rainfall area, in many places, as proved by 

 'the harvest returns, the clearly defined edge of the mallee land, 

 and equally plainly followed margin of the bluebush, &c. Once 

 Goyder's line is crossed, going northward, such trees and shrubs 

 as the mallee, Casuarina, Melaleuca, and different species of 

 acacias are practically absent ; and Salsolacese, Cassia, Bossicea, 

 the Eremian species of Santelaccc^, Eremophilse, Zygophylleae, 

 and other characteristically Eremian forms become plentiful. 

 Similarly many of the smaller plants have the same limit. 

 Since boundary lines have been laid down for all the other 

 districts, it would be convenient to define districts N and S in 

 this locality, and such a boundary I feel certain is suppHed by 

 nature and science in " Goyder's line." 



II. The Sporadic Genera and Species. 



These must, T think, make their appearance largely by the 

 transport of the seeds in the dust which is driven long distances 

 from the north and north-west by the sirocco-lik:e stormy winds 

 of midsummer and early autumn. These winds travel at high 

 speeds, have great powers of transporting dust and fine grit, or 

 any light material, and seem, by a peculiar "bearing down" 

 undulatory manner of blowing, to scoop up and raise to great 

 hei^^hts the light loose surface material on the soil. May not 

 seeds often be included in the dust, and thus be borne great 

 distances, and when alighting in favourable spots become estab- 

 lished for a few seasons at least '? 



Another manner of transport would very probably be in the 

 intestines of migratory birds. Seeds of many plants, legumi- 

 nosese, loranthacese, &c., would bear this treatment, and in many 

 cases would actually benefit by it. This region is visited 

 annually by many birds at nesting time, coming from the Far 

 North. Such are quails, the black-faced lark, dotterels, cockatoo 

 parrots, and shell parrots, among others. 



The fleeces of sheep — often travelled great distances still, and 

 necessarily more so when there were no railways — may be 

 accountable for the dissemination of many species. Indeed, a 

 more likely or more effective means of seed transport would be 

 difficult to imagine. 



The hoofs of horses, sheep, and cattle, if carefully examined 

 when having adherent mud or dry clay will often yield grass 

 seeds, and no doubt a careful and systematic examination would 

 be rewarded in the detection of many other kinds. 



The feet of shepherds' dogs carry clay, and often seeds in the 



