325 



of the typical spongy nature towards both surfaces, and corresponds in 

 character to that of the abnormal leaf. 



The central bundle is normally orientated and is supported by subordinate 

 ones about equidistant from it on both sides and in the same plane, and situated 

 medianly in the fundamental tissue. They are each surrounded bv endodermal 

 cells enclosing, in the case of the primar\- bundle at least, tracheids of the xylem, 

 the phloem, and sclerenchymatous cells on the outer edge of the latter material 

 'Figures 231-2). Midway between these and the assimilatory surface are found in 

 the fundamental tissue three or more oil glands or cavities, which are surrounded 

 by a protective sheath of cells. 



The bulk of the leaf substance is composed of irregularly-shaped cells of 

 the spongy tissue of the mesophyll with small intercellular spaces, so well seen 

 in Figures 235-6, whilst transfusion tissue is very limited in the normal leaves, 

 only a few cells being found, and these removed several cells from the protoxylem, 

 In the case of the abnormal leaves scarcely any such tissue was seen. 



(c) Chemistry of the Leaf Oil. 



This material consisted of the terminal branchlets alone and was quite 

 fresh and green. It was collected in the month of No^■ember at Woolgoolga, 

 northern Xew South \\'ales, and was steam distilled in the usual manner. 



The amount of essential oil in the leaves of this tree is very small, and 

 200 lb. of material gave onh' 5 grams of oil, which is equal to 0-005 P^r cent. 



In odour and appearance the oil resembled somewhat the inferior crude 

 oils obtained from the leaves of the CaUitvis. It apparently consisted largely 

 of the higher boiling terpenes. 



The specific gravity at 21° C. — 0-8974; refractive index at same tempera- 

 ture, 1-4977; saponification number = 4-4 or 1-54 per cent, ester, considered as 

 bormd-acetate. It was insoluble in 10 volumes of 90 per cent, alcohol. The 

 oil from the leaves of this tree is thus of little importance. 



IV. TIMBER. 



{a) EcoxoMic. 



This giant of our coast forests attains sometimes a height of over 200 feet, 

 and consequenth^ it is possible to cut some ver\' fine fiitches from it. It is a 

 whitish-coloured, easy-working, straight-grained timber, and for preference is 

 used generaUy for all kinds of indoor work, as it is not lasting on exposure. 



It is largelv used for furniture, as safes, dressers, kitchen tables, &c., 

 Occasionally it is found to possess a beautifully-grained figure. It is also good 

 for car\-ing. 



