THE STRUGGLE FOR EXISTENCE 199 
ousted it from considerable areas in the Auckland 
district. However well manuka may be equipped to take 
its part in the Struggle for Existence, it is evident that, 
for this environment at any rate, the equipment of hakea 
is even better. Associated with the manuka, and also 
covering large areas, is the bracken fern, which, unlike 
many of its relatives, is a true xerophyte, as may at once 
be judged from the hard leathery nature of its leaf. 
Moreover, the facts that the upper epidermis of the leaf 
has no stomata, and that the mesophyll is protected by a 
second layer of colourless tissue situated below the 
epidermis, both point in the same direction. Two species 
of Leucopogon (white-beard), one a dwarf plant with 
stems only an inch or two high bearing hard, pointed 
leaves and producing yellow edible drupes, the other a 
dense shrub with» somewhat larger leaves and bearing 
little branches of small white flowers, are common 
heath plants. 
On the southern heaths, in addition to the plants 
already enumerated, huge hummocks of vegetation 
formed by the Wild Irishman are often among the most 
striking features. A considerable number, too, of 
drought-resisting plants are not uncommon; but it 1s on 
the northern heaths, especially on the gum-lands of the 
Auckland peninsula, that the greatest variety of species 
appears. There we find the erect and shrubby e!ub moss 
(Lycopodium densum), Olearva furfuracea, a small tree 
of the daisy family, the dwarf cabbage tree, the 
mountain flax (Phormium cookianum) as well as the 
Gaultherias, Dracophyllums, and several of the small- 
leaved Coprosmas. 
The Sub-alpine Scrub, despite the fact that it exists 
in regions where rainfall is abundant, nevertheless, 
owing to its exposed position, is of a highly xerophytic 
character. The two commonest forms of protection here 
are leaf reduction, as seen in so many of the whip-cord 
veronicas, and the dense felt of hair formed on the 
