650 



KUThS OX THE NATIVE KLUK'A OF X. y. WALES, IX. 



somewhat limited extent east and west, and [ireseiit {xtsssibilities of 

 miiiration to the places where it now occurs in this State, it seems 

 probable that iniu-li of this distribution has occurred under condi- 

 tions of present-day topography. 



Melaleuca bracteata is the common Tea-tree along the creeks 

 north-east of Boggabri, growing in groups or clusters up to 20 

 feet high, and flowering late in November. The clustering habit 

 of these trees causes a bending over and bundling of the heads, 

 wliich render them useful for shade purposes. (Plate Ixvii.) 



The presence of such trees as Acacia pendula (Myall), and 

 Eucalyptus populif'olia (Bimble or Shiny-leaved Box), east of 

 Boggabri, shows that typical western conditions come eastward to 

 this locality, which mai'ks a point on the eastern margin of the 

 habitat of both these species. 



Ficus ruhiginosa, usually a moist-climate or coastal tree, is well 

 established on the dry summit of Barber's Pinnacle, and on other 

 hills. 



The selective qualities of jjlants, when seeking suitable conditions 

 for subsistence, are exemplified in the Euealypts and other genera 

 around Boggabri, and accord with what may be seen in a similar 

 climate elsewhere in this State. Certain trees find it necessary tliat 

 their roots should reach abundant moisture, while others have 

 adai^ted themselves to subsist where the soil-moisture is slight in- 

 ilced. Taking the three conditions of moisture at Boggabri, viz., 

 that of tlie river-banks, the alluvial flats, and the hills, it is found 

 tliat tlie rivei'-banks are occupied by Eucalyptus rostrata, while the 

 flats are covered with E. populi folia, E. Woollsiana, E. melliodora 

 and E. tereticornis, the hills and even slight ridges being the home 

 of E. alhens, E. crehra, E. melanophloia, E. dealbata and E. viri- 

 dis. 



The local Casuarinas have distributed themselves in tlie follow- 

 ing manner : — C. Cunninghamiana along the river-banks, C. Cam- 

 hagei on the flats, and C. Luehmanni on the elevations. Other 

 genera descriminate in a similar manner. 



From a study of this distribution, and adaptation to environ- 

 ment, it is easy to conceive how a process of evolution may be 



