368 



themselves ; eacli, apparently luis no connection witli the neighbouring cell 

 walls, from which they are quite free ; in fact they may be likened to so many 

 hollow glass rods in a number of tiibes. It is quite possible they may be an inter- 

 mediate stage in the formation of cellulose. They are identical in character 

 with the bast fibres of Cii/H/ris, which also ha\-e similar crystals on the outside. 



Their chemical composition was not ascertained on this occasion, as such 

 an investigation would have further delayed publication. 



At irregular inter\-als, or rather scattered throughout the bark substance' 

 are clusters of stone cells, Figure 258 (the mass in the centre of ligure from 

 top to bottom^ Two or three parallel periderm layers occur close to the outer 

 edge of the cortex, the intervening inner and outer cortex being composed of 

 masses of stone cells, parenchymatous cells, and rod-like bast cells above 

 described. No sieve tubes were found. 



(c) Chemistry. 



The bark of this tree was somewhat of a spongy nature and was astringent, 



so that a determination for tannins was made. The bark when dry was 



readily powdered, and when extracted with boiling water gave an extract of good 



colour, which acted readily on hide powder. The determination was made with 



chromed hide powder, according to modern methods, and the following results 



were obtained: — 



Total extract ... ... 19-67 per cent. 



Tannins ... ... ... 10-40 ,, 



Non-tannins ... ... 9-27 „ 



j\Ioisture ... ... ... 10-66 ,, 



The tannins gave a green coloration with ferric chloride, and the indications 

 were altogether those for a commercial tanning material, although, unfortunately, 

 the percentage of available tannin in the bark of this species is not great. The 

 non-tannins consisted largely of gum precipitated by alcohol. The bark was 

 found to contain a marked amount of starch, but no calcium oxalate was detected. 

 There was also jjrcscnt some material soluble in alkalis and precipitated again by 

 acids, and this reaction was particularly marked with dilute ammonia, the substance 

 dissolving to a purplish colour, and it had some of the other reactions characteristic 

 of Stahlschmidt's polyporic acid. It was, however, stained a deep blue with 

 iodine, and was quite insoluble in boiling water, even after some time. The 

 presence of starch in the bark, and the peculiar nature of the gum, which in the 

 jelly lorm particularly is coloured bright yellow by iodine, indicate that these 

 bodies are somewhat nearly related to some modihcation ol the nicmbcis of (he 

 cellulose group, and may, perhaps, be connected with the jxc uliar ceiiuiar arrange- 

 ment of portions of the bark of this tree. 



