EUCALYPTUS. 249 



Gippsland, a fact which he attributes to the checking of bush-fires 

 by the colonists. A table is appended showing the range in 

 altitude of the various species, and nine plates chiefly illustrating 

 the characters derived from the older and younger leaves, anthers, 

 flower-buds, fruit, &c. In the same volume McAlpine and 

 Eemfrey have a paper on " The Transverse Sections of Petioles of 

 Eucalypts as Aids to the Determination of Species." Sections of 

 thirty different kinds are described and photographed, showing 

 unmistakably, along with a general resemblance, differences which 

 are more or less constant and readily recognisable for each species. 

 The organs and parts chiefly relied on as furnishing specific 

 characters are the epiderm, the hard bast, the xylem with its 

 vessels, the cortical cavities, and the central canals. The size and 

 shape of the transverse section of the petiole is also often 

 characteristic. 



Sig. G. Briosi has recently undertaken an exhaustive investiga- 

 tion of the anatcmiical structure of the leaves of E. glohUus* The 

 leaves are of three kinds, the cotyledons, the earlier horizontal, 

 and the later vertical leaves, the last two passing into one another 

 by insensible gradations. The vertical form is regarded as an 

 adaptation to the intensity of the light, in order to prevent too 

 great transpiration. The glands in the leaves are apparently also 

 a protection against the action of heat. The glands are distributed 

 abundantly, but irregularly, through the tissues of the leaf, and 

 occur even in organs which are destitute of stomates, as the 

 petiole, receptacle, ovary, &c., and occasionally, though rarely, in 

 the pith. They are of lysigenous origin, the neighbouring cells 

 are modified in structure, the wall adjoining the gland no longer 

 yielding the cellulose reaction ; and these walls combine so 

 completely that the gland has the appearance of a closed sac. 



When Eucalpytus leaves are carefully dried in the shade they 

 are found to lose moisture as follows : — 



E. amygdcdina ... ... loses in weight 50 per cent. 



E. globulus ... ... „ 50 „ 



E. ximincdis ... ... „ 41 „ 



E. rostcda... ... ... „ o^ „ 



(Eaveret-Wattel). 



* Ricerche intorno all' anutomio delle foglie dell' Eucalyptus Globulus, 23 

 pi., Milano. 



