OCCURRENCE OF CALCIUM OXALATE IN EUCALYPTUS JBARKS. 25 



of crystallised calcium oxalate seems, therefore, to be 

 common to the barks of the Eucalypts, but while in some 

 of these the calcium oxalate is present in great abundance, 

 in other species it occurs only in very small amount, as in 

 the bark of E. Morrisi, for instance. The mallees which 

 contain the crystals in greatest abundance, seem to be 

 those species which have a very thin smooth bark, or at 

 most a little persistent bark at the base, this is shown with 

 E. Behriana, E. gracilis, and E. oleosa. It does not follow, 

 however, that the thin barks always contain calcium oxalate 

 in abundance, because the barks of E. stricta and of E. 

 polybractea are both thin and smooth, and contain but a 

 small amount of that salt. In the thicker and more fibrous 

 barks of E. Morrisi and E. viridis (the thin barks of these 

 species were not determined) crystals were sparsely 

 distributed. 



Mr. S. J. Johnston of the Technological Museum has 

 kindly measured crystals of various species, the mean 

 results being as follows : — 



General type, length 0*01746 mm. breadth 0*00776 mm. 

 E. gracilis „ 0*01552 „ „ 0*01164 „ 



Ditto, prisms „ 0*0175 „ „ 0*00679 „ 



E. polybractea „ 0*0291 „ „ 0*00582 „ 



Mr. R. T. Baker, the Curator (to whom I am indebted 

 for botanical assistance in preparing this paper) had already 

 informed me that on botanical evidence of buds, fruit, 

 leaves, and timber, he could distinguish no difference 

 between E. salmonophloia of West Australia and E. oleosa 

 of this State. Through the kindness of the authorities of 

 West Australia, the leaves of E. salmonophloia were for- 

 warded to the Museum for investigation, and the oil of 

 this species was found to consist of the same constituents 

 as had previously been obtained from E. oleosa, and allow- 

 ing for rather more pinene in the oil of E. salmonophloia, 



