312 A. A. HAMILTON. 



are established among the boulders. The drastic change 

 in the conditions on the headland has compelled the plants 

 to reduce their bulk, diminish and toughen their foliage, 

 and encourage a twiggy growth in their branches. 



In a sheltered hollow in which a swampy seepage has 

 collected, a patch of Bceckea crenulata R. Br., is estab- 

 lished. This shrub presents a considerable divergence in 

 habit and height of the plants, and in size and arrangement 

 of the leaves, within its coastal boundaries. In his descrip- 

 tion of the species, Bentham (PI. Austr., iii, 78), allows a 

 margin in the length of the leaves from \\ to 3 lines. The 

 plants on Deewhy Head average 18 inches in height, with 

 leaves 2 lines long. This form is also found in swampy places 

 in the Centennial Park, and extends via Hornsby to the 

 Blue Mountains, in similar situations. 



On the exposed frontal ledges of the parapet above the 

 ocean escarpment, this small leaved form is prostrate and 

 matted, but gradually assumes an erect habit as it retreats 

 from the verge. In the soil pockets on the broken cliffs of 

 the ocean escarpment at Manly, Bondi, etc., a form occurs 

 with symmetrically decussate leaves 4^ lines long, which 

 reaches a height of 3 feet. Growing side by side with this 

 form, plants of a similar height were noted, whose leaves 

 were slightly smaller, more distant, and not strickly decus- 

 sate. A closer scrutiny revealed the two forms as young 

 and old plants, the former with succulent, closely packed 

 leaves, regularly arranged in opposite pairs, and the latter 

 with shrunken leaves, a sufficient number of which had 

 fallen, to obscure the decussate alternation, and completely 

 alter the facies of the shrub. Both forms are depicted in 

 Illustr. Cook's Voyage, ii, tt. 103-104, the former, a twig 

 from a young plant, representing the typical species, and 

 the latter, a twig from an old shrub, the var. tenella of 

 Bentham. Both forms of the taller, large leaved shrubs — 



