Cockayne. — Plants of Chatham Inland. 281 



this latter plant grows at times on all the forest trees, it is by 

 far most frequently met with on the smooth bark of Coryno- 

 carpus laevigata. Even where Corynocarpus is without the 

 forest it often affords a home for this fern, which in such 

 stations of extreme dryness grows most luxuriantly. 



The lowland forest occurs in all parts of the island except 

 on the tableland. In the neighbourhood of the Horns and 

 at Te Awatapu the forest is intermediate in type between 

 that of the lowland and tableland, the result perhaps of in- 

 termediate edaphic conditions. The most extensive lowland 

 forest now existing is that between Petre Bay and Te 

 Whanga. The volcanic hills, Korako, Wharekauri, and 

 Maunganui, are forest-clad. In the neighbourhood of Wha- 

 ngamarino there is a forest of considerable size bordering on 

 Lake Huro and covering the adjacent slopes ; and finally 

 lowland forest fringes much of the coast-line, as was shown 

 when dealing with the sand-dunes. It has been explained 

 how a forest may originate in a swamp ; but, besides this, the 

 beginnings of forest may be seen in those patches of " bush " 

 which line the bottoms and sides of gullies, such gullies 

 having been hollowed out by the action of streams. In such 

 sheltered positions, where the drainage conditions are good, 

 trees can easily take possession of the ground, and from 

 thence may spread out on to the neighbouring slopes or flat 

 land. 



Heath. 



One of the most important factors which determines the 

 presence or otherwise of forests is wind. Where constant 

 high winds are the rule, even though every other condition is 

 eminently favourable, very few trees can gain a footing on the 

 ground, while if such have in addition to contend against 

 other plants better equipped for the contest, especially such 

 as are provided with strong subterranean members, they must 

 succumb. This accounts, I believe, for the absence of forest 

 over much dry ground quite suitable for its reception and 

 maintenance. For the plant-formation of such ground I pro- 

 pose the term ''heath" rather than "meadow," since the 

 latter name suggests the presence of grasses as the dominant 

 plants, whereas here these latter are in the minority, and 

 bracken fern is the most important constituent. The whole 

 of this formation, no matter where it occurs on the island, is 

 a modified one, so no exact presentation of its original aspect 

 is possible. It seems to follow directly after the bog forma- 

 tions, and it may, I think, replace them without any inter- 

 mediate stage of tear ia-Dracophy Hum bog or Dracophyllum 

 scrub having occurred.* 



* For meaning of these terms, see " Bog Formations," further on. 



