526 Mr. Hinds on Climate, ^c. — Soil. 



where also there will be an admixture of the other salt-water 

 constituents. 



A number of particular plants are generally found attached 

 to old wallsj or among the ruins of deserted buildings^ where 

 the source of attraction is the nitrate of lime and potash ex- 

 isting in the old mortar ; among these are Parietaria offici- 

 nalis, Urtica dioica, Antirrhinum majus, Linaria cymbalaria, 

 Hieracium pilosella and some other species^ Arenaria serpyl- 

 lifolia, &c. 



In no country is vegetation so sure a guide to the qualities 

 of the soil as in New Holland : the different visitors speak with 

 confidence on this subject, and represent the settlers as guided 

 in their choice of a location by the nature of the sustained ve- 

 getation. Angophora lanceolata, the native apple, indicates a 

 good soil ; the spotted gum and stringy bark a bad ; the 

 Australian mahogany is found on white sand ; and the red and 

 blue gum, both species of Eucalyptus, select clayey districts ; 

 the numerous Banksia and Protea are sand-loving plants. 



Von Martius was agreeably surprised at seeing some arbo- 

 rescent lilies on elevated lands in the Brazils ; they consisted 

 of several species of Villosia and Barbacenia, and appeared 

 only to thrive on quartzy mica-slate. The allspice, Pimenta 

 vulgaris, is cultivated with profit only on white limestone. 

 Many of the Cellulares adhere with much tenacity to parti- 

 cular kinds of rock, and among them lichens are especially 

 distinguished. From Sir Wm. Hooker's ^English Flora,' where 

 some discrimination has been used in assigning a locahty, I 

 have calculated the following distribution : — 



Attached to trees , 144 



Attached to posts and shingle boards .... 35 



Epiphytic or other agamies 11 



Growing on heathy soils 24 



Growing on soils usually sandy 30 



Growing on old walls 16 



Growing on bricks and tiles 7 



Attached to rocks generally 97 



Calcareous and limestone rocks 19 



Flinty stones 11 



Slaty rocks 9 



Sandstones, white and red , . . . . 8 



Whinstone 4 



Granite 3 



Quartz 1 



or, considered in another view, attached to organized sub- 

 stances 190, to mineral 175, and to what may be called neu- 

 tral 54 J making a total of 419 species. 



