196 HORN EXPEDITION — BOTANY. APPENDIX. 



determined in the small portion of material forwarded. The resin obtained 

 from Triodia irritans, R. Br. by ether, in appearance and colour resembles that 

 obtained from Triodia pungens, but it has a lower melting point, melting at 

 63° C. Tlie brown resin obtained by alcohol, corresponding to that obtained 

 by alcohol from Triodia pungens, melts at 102° C. From the results of the 

 examination of the bodies contained in the resinous material of Triodia irritans ?* 

 it was suggested that the fat found was artificially introduced ; its presence would 

 lower the melting point of the resin. Judging from the appearance of the two 

 resins, their colour, odour, melting points, etc., there appears to be but little 

 difference in the I'esins obtained from Triodia pungens and Triodia irritans, and 

 they may prove to be identical when prepared under similar conditions. 



We have so few records of the finding of the Porcupine resin, that the following 

 is of interest: — "Samples of resinous matter from roots of Spinifex, and tunnels 

 made by ants, found here for the first time, lying on the surface of the sandy 

 ground between bunches of Spinifex, apparently made of sand cemented with 

 some agglutinous secretion of the insect, or, what is more probable, the resinous 

 substance found at the roots of the Spinifex plant." (VV. T. Tietkens' Exploration 

 of West Central Australia, in Trans. Roy. Geog. Soc. Vict., viii., 35). 



No. 2. Gum of Atalaya heniiglaiica, F. v. M., Central Australia. Most of this 

 gum is quite colourless, and adherent to pieces of the wood of the tree, which belongs 

 to the natural order Sapindaceie. A very small quantity only was received. It is 

 readily soluble in cold water, from Avhich solution alcohol throws down a white 

 precipitate readily .soluble in water but insoluble in alcohol, and resembling arabin 

 in its properties. It is pure gum and appears to differ little from the purest Gum 

 Arabic. A portion of the gum is also attached to a covering of the exterior of the 

 bore of a wood moth (probably a species of Cryptophasd) made of silken web, with 

 castings and debris attached. This gum would be a valuable article of commerce 

 if obtainable in quantity. 



No. 3. Kino of Casuarina Decaisneana, F. v. M., near junction of Rivers Finke 

 and Palmer. The material, received 26th April, 189-1, consisted of portions of the 

 tree coated with a dark brown resinous looking material which substance also filled 

 the hollows of the lumps. At places it had a varnishy appearance, but the greater 

 portion was a dull dry looking mass of an umbery colour. When powdered and 

 treated with water a reddish-bi'own solution is obtained, which consists principally 

 of a tannic acid giving a dirty purplish colour with ferric chloride and precipitable 



» See a paper by me on " Spinifex resin," Proc. Linn. Soc. N.S.W., (2), vol. iv., p. 039, 1889. (A gum used by 

 tlie blaelts for cenientiny the ends of spears and prepared from Spinifex roots). Collected at Napier Range, W.A. 



