space for the windings of streams which originate in its 

 eastern flanks, ere they are discharged into the ocean. On 

 other coasts, as upon one part of the north — upon the western 

 (as inland from the Swan River) — and on parts of the southern 

 shores of that continent, have been observed, ridges of hills ; 

 but these are isolated, or rising from the surface of a compa- 

 ratively level country, present no trace of connexion, either 

 with the great eastern chain, or with each other : and they 

 are all of inferior elevation, no one exceeding 3000 feet of 

 perpendicular height above the level of the sea, and most of 

 them of not half that elevation. It may be here remarked, 

 moreover, that with reference to the face of the interior, every 

 observation of the traveller goes to support the theory, that 

 although detached hills and even some ridges have been 

 noticed on its ample surface, neither a chain of mountains, 

 nor any elevated points to form the nucleus of a second main- 

 range exist in the central regions of the continent, which will 

 one day be rather found a vast level, through which its 

 rivers, if they exist far from its eastern side, have, from the 

 prevalent disposition of the country generally to drought, 

 much to combat in their efforts to gain any sea coast. 



From these brief remarks of the structure of the Austra- 

 lian continent, it will be seen that the eastern coast, or that 

 of New South Wales, within and beyond the tropic, is the 

 only shore to which we can look for Epiphytic Orchidaceae and 

 for Filices and other of the Cryptogamic class— in fact, the 

 only one (if we except one or two points of the north coast, 

 strictly so called) on which these orders of the vegetation of 

 that great country have hitherto been found— its main chain, 

 which in some parallels has been found to measure 6000 feet 

 above the sea shore, furnishing in its ravines and rocky 

 flanks, ample shade and humidity to the sustenance of those 

 families ; but in several islands in the Gulf of Carpentaria, 

 says Mr. Brown, " having a flora of phcenogamous plants ex- 

 ceeding 200 species, I did not observe a single species of 

 moss"— and this, evidently, because of the ordinary elevation 

 of those isolated spots; the consequent little shade they 

 afford; and the extreme dryness of the circumambient atmo- 

 sphere. 



With the requisite conditions of high temperature and con- 



