PRESIDENTIAL ADDRESS. 43 



Other mountain Eucalypts whose seedling leaves are 

 very much larger than their adult foliage, and are opposite 

 for a few pairs only, but are not sessile, are E. Delegatensis 

 and AndretvsL 



In the Coastal Area some of those species which show 

 the diverse forms and have juvenile leaves both sessile and 

 cordate are E. quadrangulata, which ascends the mountain 

 to about 2,000 feet, E. radiata which ascends to about 

 2,500 feet, E. Smibhii which ascends to about 3,000 feet, 

 E. umbra, and melanophloia on the Upper Clarence. There 

 are others which show extremes in size but whose seed- 

 lings have very few opposite pairs, amongst which may 

 be mentioned some forms of Eucalyptus tereticomis, 

 siderophloia, hemiphloia, and Planchoniana. 



On the Western Slopes, the Eucalypts which show 

 extreme forms of foliage and have sessile juvenile leaves 

 are E. melanophloia in the north, E. Cambagei on some of 

 the hills and E. Bridgesiana on some of the flats, but the 

 home of the latter two is chiefly on the mountains. 



There do not appear to be any species of Eucalyptus in 



the Interior whose seedling leaves are sessile and cordate, 



excepting E. melanophloia. The form, however, is not 



wholly absent from some of the dry portions of Australia. 



Clothing of Leaves. 



Among the familiar forms of leaf coating for the purposes 

 of affording protection are the development of fine hairs 

 and tomentum, the secretion of wax and viscid substances, 

 the coating of the leaf with caoutchouc, and the thickening 

 of the epidermis. Of these methods the Eucalypts of New 

 South Wales chiefly adopt the thickening of the epidermis, 

 the wax covering, and in some instances the caoutchouc 

 coating on the Juvenile leaves. 1 



1 See a paper " On the Elastic Substance Occurring on the Shoots and 

 Young Leaves of Eucalyptus corymbosa and some species of Angophora," 

 by H. G. Smith, f.c.s., this Journal, Vol. xlii, p. 133, (1908). 



