Is the Eucalyptus a Fever-destroying Tree ? 15 



Again, the mallee scrub is the opposite of all ' this. 

 Properly this scrub consists of three species — the oleosa, the 

 dumosa, and the socialis, but I have brought them under 

 consideration as one, the oleosa. They are the dwarfs of the 

 eucalypti, but seldom growing higher than 25 feet, and are 

 more like saplings than trees ; they occupy a dry, flat, 

 hungry country, with but little growth of grass under them, 

 chiefly dwarf heath bushes ; there is little rain, but when it 

 comes it is generally in torrents ; the soil is a reddish sand, 

 in combination with salt clay; this during the long droughts 

 becomes exceedingly hard, so much so that a p ickaxe is 

 required to turn the soil. The roots run somewhat in a 

 horizontal direction, and the rootlets spread out travelling 

 downward ; and as salt water is to be obtained always at 

 from 25 to 40 feet, they are found resting on the moisture of 

 the salt soil, just above the sandstone rock, which generally 

 commences about 12 feet above the salt spring. The 

 temperature of the surface ground, and also that of the air, 

 is very high throughout the summer. The leaves supply a 

 greater amount of oil during the winter, or rainy months, 

 than during the hot, or summer months. 



These two examples of opposite conditions at one and the 

 same time present themselves to my mind thus — 



That too much rain out of season renders the amygdalina 

 and the other sea-ward species poor in volatile oil ; and that 

 the early and latter winter storms of the interior, place the 

 desert species in the same oil condition as those of the 

 amygdalina and its allies. Hence the mallee supplies an 

 abundance of oil during the moist season, and the coast 

 species during summer. 



We have, therefore, a eucalyptus vegetation charged to its 

 utmost from September to April around all our populated 

 districts, and we have another in the desert species charged 

 in like manner from May to October. In other words, as 

 midwinter approaches, the coast species are increasing in 

 volatile products and the others are decreasing. 



In proof of this I give the following : In December and 

 January the desert eucalypti are sending forth at the top of 

 their thick foliated branches, new sprigs filled with new leaf 

 development, and notwithstanding their small and delicate 

 structure, they are full of oil cells with scarce a trace of oil 

 in them ; and in a degree a similar impoverished condition 

 exists in the old and matured leaves. (Specimen shewn.) 

 This again is the very opposite to the amygdalina, the 



