AUSTRALIAN TREES AND SHRUBS. 99 



since the narrow edge and not the broad surface of the leaf 

 is directed towards the sun. A further peculiarity noted in 

 Eucalyptus trees is that it usually takes at least twelve months 

 for the flower buds to reach maturity and another year for 

 the fruit to mature. There is little doubt that for the most 

 part the flowers are fertilized by honey-feeding birds. The 

 seeds are retained and remain quite fertile for several years 

 in their woody capsules, which in some cases open their valves 

 only when exposed to forest fires. Seedlings usually spring 

 up in consequence in burnt-over lands. Again, many species 

 when killed by fire rapidly regenerate by suckers from the 

 roots. 



The formation of adventitious shoots or suckers is character- 

 istic of all Australian gum trees. It is noticeable what a 

 great contrast exists between the leaves of these suckers and 

 the adult leaves ; it is more marked than anything we see in 

 trees in this country. Where large masses of Eucalypts of a 

 shrubby character cover the country, they are usually known 

 as " Mallee." In these there is usually a knotted root-stock 

 from which many stems spring. It is seldom that any 

 specimen in a " gumscrub " attains the dignity of a tree. 

 When it is proposed to clear mallee for agricultural purposes 

 the whole is sometimes crushed down by means of heavy 

 rollers, and when dry it is afterwards burned. When similar 

 shrubby growth is composed of acacia it is called " Mulga." 



EUCALYPTUS OIL AND TIMBER. 



The bark, resin, and oils of Eucalyptus trees are well-known 

 commercial products. Eucalyptus oil is described as 

 probably the most powerful antiseptic of its class, especially 

 when it is old, as ozone is formed in it on exposure to the air. 

 It does not, however, serve as a substitute for quinine in 

 malaria. Further, in large doses it acts as an irritant, and 

 is a marked nervous depressant. The oil has acquired an 

 extraordinary popular reputation in influenza ; but there is 



