EUCALYPTUS. 43 



in the middle interior. We lose little in losing the 

 obliqua as a tree to recommend compared to the jarrah. 

 This latter tree is reported to be teredo proof. It has 

 been extensively used for piling and also for railroad ties 

 in parts of India subject to the white ant. The reputation 

 of the jarrah rests as to teredo resistance on the early 

 constructed Australian wharves. It may be that the teredo 

 was not native to Australian waters. The natural absence 

 of the teredo, at least from the open coasts of California, 

 has been asserted and the frequent wharves built out into 

 the placid waters of the Southern coast are said to have 

 at first enjoyed an immunity from teredo attacks. We 

 have a very injurious pile enemy, even worse than the 

 teredo that works only at the tide limits of the piles. 

 This is the limnoria. 



The early Australian experiences may have been due 

 to an absence of teredo. A careful inquiry shows that sev- 

 eral other species are very distasteful to insects. The most 

 resistant of these are the Eucalyptus rostrata red gum, 

 Eucalyptus robusta swamp mahogany, Eucalyptus diversi- 

 color karri. 



This advantageous characteristic seems to depend on the 

 wood of these trees containing a large proportion of kino- 

 red. Frequent experiment in Australia has shown a marked 

 difference in the amount of kino-red in the same species of 

 Eucalyptus. The jarrah growing in light soil and gener- 

 ally in the open lowlands is very deficient in kino-red as 

 compared to the trees growing on the strong iron soil of 

 its native mountains. The jarrah, red gum and karri 

 each contain a maximum of from 16 to 17 per cent, of 

 this substance while the robusta contains 19 per cent, and 

 exceeds all Australian trees in kino-red. 



