104 



utilising the inner bark, which has some tenacity, in the direction indicated. If a cheap 

 method can be devised, it will doubtless be applied to the inner fibre of many other 

 species, utilised already as a rough tying material. 



The bark of E. sideroxylon, grown in South Africa, is being tested as an insulating 

 medium in cold-storage work, see " The South African Journal of Industries," March- 

 April, 1921, p. 271. The fibre of this species has properties in the direction of corkiness 

 or non-conduction of heat, rather than that of tenacity of fibre. 



16. COLOUR OF INNER BARK. 



The inner bark in Eucalyptus may, when quite fresh, be quite pale-coloured, 

 (" white,") yellow, of various degrees of intensity, to orange, and even brown and red. 

 These colours are probably due to tannins, and, particularly as regards the yellows, it 

 would be desirable to invoke the aid of the chemist. 



The bright yellow of the inner bark of E. melliodora is so characteristic that the 

 name of the tree is " Yellow Box " because of it, and one chips off a little of the bark 

 with a tomahawk in all cases of doubt. I remember, at a time that E. Bosistoana was 

 but little known, and its range far less worked out than it has been since, coming across 

 a tree in the Liverpool district (N.S.W.) called " Yellow Box." A chip showed the inner 

 bark to be non-yellow, and therefore it could not be E. melliodora. It turned out that 

 it was known as Yellow Box because of the yellowish colour of the wood, but the colour 

 of the inner bark at once showed the difference between it (E. Bosistoana), and the 

 original Yellow Box (E. melliodora). 



I have a note in regard to the yellow inner bark of E. Mnelleriana, the stain 

 sometimes penetrating through the wood, at Part VIII, pp. 220 and 236. Other Stringy- 

 barks, perhaps all of them, have yellow inner barks, e.g., E. capitellata, E. macrorrhyncha, 

 E. eugenioides, E. kcvopinea. E. cladocalyx has a thick, sappy bark of a rich orange 

 colour. 



E. acacioides has an inner bark of an orange colour, but I do not know whether 

 this colour is practically constant. I feel in this, as in so many other aspects of the 

 big subject of Eucalyptus, I am but offering a pointer to others. We want the accumu- 

 lation of facts, and then we can group them and, later on, make deductions concerning 

 them. 



17. COLOUR OF OUTER BARK. 



These notes on colours apply only to the Gums, and they vary to some extent 

 with locality and season of year. For further notes on colours see under E. stellulata, 

 pumila, Bamerhni, Behriana. In all these species we have greenish barks at one season 

 or another. Sometimes they are oily green, and sometimes olive green, and sometimes 

 shade off into a lead colour. 



E. hcemastoma also sometimes exhibits a brown colour, and so do the Grey Gums 

 ( E. punctata and E. propinqua). The Gums display a variety and intensity of colour 

 during the year, and in different years, and I regret I have not brought my notes on 

 the subject together. 



