66 1 



ami at C and I), the soils are fairly good. Thus, by a knowledge of 

 the underlying rocks, \vc can judge of the fertility of the soil. Yet 

 this knowledge is not without its disturbing elements, as in the 

 case of rocks which are cove-red by alluvial deposits that may have 

 been carried from some distance. These cases are tew, and at any 

 rate ihe soil generally contains a large proportion of the rock it 

 overlies, or those in close proximity to it. On the coast line there 

 are to be found some place's where a deposit of arenaceous sand 

 has taken place, where the soil has no relation to the underlying 

 rocks. These deposits of sand are carried by the winds from the 

 sea shore inland, and deposited in greater quantities in some places 

 than in others, owing to some physical contour of the land. But 

 these do not disturb the general conclusions of judging the fertility 

 of the soils by the rocks they are formed from. 



There is another method of judging the value of soils and 

 their adaptibility to certain crops, which I may call that of natural 

 ^election. It is a well-known fact that certain plants are only found 

 growing in certain soils, but these selections are modified by 

 climatic influences. The selection may be extended to more than 

 one class of soil, owing probably to these soils containing some 

 element of food conducive to the growth of the plant, but generally 

 other plants are found growing with it that point to an alteration in 

 the nature of the soil from that in which it is generally found. 



The following is taken from Mr. A. Despeissis', M.R.A.C., 

 flamibook of Horticulture and Viticulture, tirst edition : 



<4 In the ironstone gravel soils are to be found the following 

 trees giving indications -of soils of various degrees of fertility. 

 Underneath the ironstone gravel soil is to be found a clay at various 

 depths, which is generally indicated by the growth of the following 

 trees: (iravelly ironstone is indicated by jarrah, but where there is a 

 certain depth of brown loam the jarrah is associated with grass 

 trees or blackboys. Pockets of deep loam amongst the ironstone 

 gravel are indicated by red gum trees, and wherever jarrah, red 

 gum and blackboys grow together and attain large proportions, there 

 the soil is c rtain to be deep, well-drained, and fertile. Pipe-clay 

 is revealed by the presence of white gum trees. White gum alone 

 is an indication of the predominance of pipe-clay, or of a cold 

 retentive clay and gritty sand soil. Small blackboys growing 

 amongst white gums are evidence of the presence of this stratum 

 of loam on the surface, Jarrah and white gum growing together 

 are indicativ of a mixture of ironstone gravel and pipe-clay. 

 Flooded gums are often associated with blackboys alongside brooks 

 and on alluvial soils bordering water courses, and mark out fertile 

 strips of land rich in potash. In the south-west district the yate 

 tree grows on such soil. Chocolate loam, sometimes of great 

 depth, varying in texture from a heavy loam, is characterised 

 by a greater or smaller admixture of the York gum tree, 

 to the wattle or jam tree. Such land marks splendid corn 



