•60 NOTES ON NATIVE FLOliA OF NEW SOUTH WALES, VI., 



almost to the New England Plateau, but this it accomplishes by- 

 creeping up the sides of the valleys where it secures shelter from 

 coastal influence, for its great desideratum is a western aspect. 

 North of Emmaville it follows up the valley of the Beardy River 

 aud Glen Creek, gradually establishing itself at such high levels 

 -as to come within some of the winter snow-storms. It advances 

 towards Glen Innes along the valley of the Maclntyre River 

 -above Inverell, where the basaltic formation suits it so admirably, 

 and is the principal tree in giving a characteristic appearance to 

 the local flora. 



Reflecting on the qualities which a plant possesses for resisting 

 extremes of temperature and moisture, the thought is suggested 

 that possibly in some instances after thousands of years of 

 gradual adaptation to opposite conditions, extreme forms are 

 evolved which in time may be regarded as separate species. 

 Something of this kind may explain the great similarity which 

 •exists between E. albens of the west and E. hemiphloia F.v.M., 

 a common Box tree along the coast. It is still a matter of 

 opinion among botanists whether these are two distinct species, 

 or one a variety of the other; but it seems highly probable, con- 

 sidering the close affinities between them, that both had a com- 

 mon origin, and have developed their present characteristics 

 owing to the various influences of environment. 



A gum tree often associated with E. albens in rocky situations 

 is E. dealbata A. Cunn. (E. tereticornis var. dealbata Deane & 

 Maiden). This is a tree with strong affinities to E. tereticornis, 

 and may perhaps be justly regarded as only a variety of that 

 species. In these Proceedings for 1900 (p. 7 12) I have suggested 

 that E. dealbata may perhaps be regarded as a form of E. tereti- 

 cornis which grows chiefly on ridges, and incline to the opinion 

 that it may be considered as a variety, although characteristic 

 differences are referred to. During the intervening years a close 

 study of the habit and distribution of these trees satisfies me 

 that there are fairly constant differences between them sufficient 

 to make it desirable that E. dealbata should rank as a species. 

 The chief botanical differences appear to be in the truncate and 



