166 THE INSTABILITY OF LEAF-MORPHOLOGY, 



such an extent that the leaves of plants of this species, growing 

 in a habitat unaffected l^y salinity, show as much variation 

 relatively to the succulent form, as that obtaining between the 

 leaves of two distinct species of this genus, e.g., B. Gunniana 

 Schau., and B diosmifolia Rudge. 



The growth which oppeared on some bushes of the latter at 

 Valley Heights, after a fire bad run tbrougii theui, presented a 

 marked difference from that obtaining in the foliage of the un- 

 scathed plants. B. deasifolia 8m., exhibits a foliar difference in 

 examples growing in a sheltered position at Valley Heights, and 

 those growing at Newnes Junction (3500 feet) exposed to the 

 bleak " Westerlies" (13: 1914, p.254). The leaves of the xero- 

 phytic, coastal swamp-form of Darwinia taxifolia A. Cunn., are 

 inferior in luxuriance to those of the same species growing on 

 the poor but well drained sandstone-hills at Cowan. 



An example of leaf-variation within a species, is given in Anyo- 

 phora melanoxylon R. T. Baker. In his description of this 

 species, the author writes: — "The rare shape of some of the 

 leaves (the lanceolate form) connect it with A. inter-media, whilst 

 the rounded, auricular base of the predominant shaped leaf gives 

 it some aftinity to A. subvehitina" (These Proceedings, 1900, 

 p. 85). A series of leaves of A. cordifolia Cav., showing varia- 

 tion within this species was noted (13: 1915, p. 487). Specimens 

 showing leaf- variation in the suckers of a form of A. intermedia 

 DC, taken from a series of young trees (over which a fire had 

 passed), growing on the Wianamatta Shale, near Clyde Rail- 

 way-Station, are here noted. Example 1 : two, lower whorls of 

 sucker-leaves ternate, the remainder gradually passing into the 

 adult stage, and all opposite. Example 2 : two, upper whorls of 

 adult leaves ternate, with a pair of opposite, adult leaves imme- 

 diately below, merging into the sucker-leaves, which are all, from 

 these downwards, alternate. Example 3 : juvenile and adult 

 leaves, all opposite. Example 4 : lower whorl of sucker-leaves, 

 ternate, those above opposite. Example 5 : three, lower whorls 

 ternate, and one pair above, opposite (all juvenile). Example 6 : 

 all sucker-leaves ternate. An exceptional range in size, shape 

 (basal and apical), length of petiole, etc., is shown in both the 



