173 



II. SYSTEMATIC. 



An a\-erage, foliaceous Callitris tree, attaining generally 50 to 60 feet in 

 height. The leaves are glaucous and not dorsally ridged, the free portion more or 

 less spreading, acute, and proportionately long. Male amenta ovoid, terminal in 

 twos or threes. Female amenta below the ultimate branchlets. 



Fruit cones spherical, wrinkled, under \ inch in diameter, valves alternately 

 large and smaU, comparativel}- thin, dorsal point fairly prominent, the central 

 columella ver}- short, rarely lengthened. Seeds one-, two-, and three-winged. 



The main points of differentiation of this species from C. arenosa are the 

 timber, bark, and the chemistry of its several parts. 



III. LEAVES. 



(a; Economic (vide Chemistry, infra). 

 (b) Anatomy. 



These sections are characterised on the dorsal side by (1} the flattened 

 or oblong epidermal cells with specially thickened walls, (2) the double row of 

 h^'podermal cells, (3^ the packed pahsade tissue, and (4) the preponderance of 

 loose, spongy mesoph}il. 



To these might be added the comparatively small number of parench}-- 

 matous, endodermal cells and tracheids of the transfusion tissue in the \dcinity 

 of the central axis of the branchlet. The stomata are found in the ventral channel 

 formed b\- the leaves, on the inner side of the free portion of the leaves, as well as 

 at the base of the decurrent portion immediatelv facing it. The usual elongated 

 projections of the cuticle also occur here. 



Figures 107 and loS are cut just below the oil ca^ities in the upper part of 

 the leaves, and weU illustrate the predominance of spongy mesoph\'U in the leaf 

 substance, and the small proportion of parenchymatous endodermal cells ; the 

 transfusion tissue is well indicated bv the pitted cells, and these latter details 

 are more clearly shown in Figure 109 — a 200-magnification. Figure no 

 illustrates a cross-section cut through the three oil ca\ities. 



The salient feature in the anatom_\- of the leaves of this species, is the 



^delicate structure of the spongy tissue, and in cutting, it is very difficult to obtain 



sections whole, the central axis and its adnate cells generally tearing away 



from the fundamental leaf tissue, which is traceable b}' delicate lines in the figures 



here gi^"en. 



