366 



have been able to ascertain, for apart from other Uistnicti\e features there 

 appears to be no regular concentric layers of cells such as one finds in the 

 Callitris, and figured in this work. From the cambium outwards the whole 

 collection of cells and fibres is a complete medley, and e\en the medullary rays, 

 which almost in\-ariably preser\-e some disposition in conformitx' to their name, 

 fail in this respect in this species of Araucaria. 



The medullar\' rays run througli the bark in a sinuous course and are 

 thickly studded with starch granules, distinctly seen in h'igure 256. The rays 

 are not many cells high, and only one in width, and can be traced running 

 obliquely across the picture in Figure 255, which is not so great a magnification 

 as the coloured Figure 256 ; the}^ became less in definition as the outer cortex is 

 reached. 



The rest of the material between the cambium and periderm bands which 

 forms the extreme outer layers of the cortex, is composed, apparently, of two 

 forms of cells, viz., the sclerenchymatous fibres, and short parenchymatous cells 

 either empty or starch containing. In shape and perhaps character, the former are 

 quite in accord with Australian Conifers as far as our knowledge goes, and possess 

 features which occur in barks other than in this genus. They are true canals in 

 character, having no septa, but preserve an unobstructed direct communication 

 with the roots, from which each extends as a continuous body or substance ; 

 when viewed in cross-section (Figure 256) they are rectangular in shape, with 

 thickened borders, the substance extending to the central canal being of a lami- 

 nated structure, apparently formed by deposition from fluid content similar 

 perhaps to deposits of carbonate of lime found in tubes or pipes, formed from 

 water carrying this mineral in solution. The median channel is well shown in 

 Figures 256 and 260. The continuity and solidity of this substance is seen in 

 Figure 260, where, after all the surrounding tissue has been removed, they remain 

 intact, whilst still a part of the surrounding cell is embedded or contained in solid 

 bark material. 'I'he median line seen is the central channel. A cluster of 

 parenchymatous cells are shown at the bottom between the two left bast fibres. 



Under a quarter-inch objectixe it was found tiiat the sides and ends of this 

 substance were thickly studded with crystals of a rhombus form similar to those 

 figured in De Bary, p. 132, after Sach, and wlio describes them as crystals of 

 calcium oxalate ; but ours are not that substance as proved by chemical tests ; 

 but what they are we are not prejmred to say at present as they recpiire further 

 investigation, and the same remarks apply to the body substance itself. These 

 long rod-like bodies have been classed as scleren( li\ nia liiircs, f)r basl ( ells. I hey 

 certainly do not differ much from the bast cells of Callitris in structurr, and 

 form, as it were, part and parcel of the whole matrix. These substances appear 

 to be formed by the slow deposition (jf Wv alldid li(|nid mo\'ing in tlie rells 



