128 The Plant Formations. 
scandens, forming entanglements beneath which one is compelled, at times, to 
crawl on hands and knees. In other places, the hooked prickles on the mid- 
ribs of Rubus australis, catching a garment, may hold one fast. Furthermore, 
even on level ground, there are wäter-courses, here and there, and near these 
the density of the undergrowth increases, fateral branches from the trees on. 
either side meet and become entangled, the growth of ferns becomes thicker, 
so that progress is well nigh impossible. In hilly forest, the density of gullies 
is still more intensified. y 
The close growth, which I have attempted to describe, is in harmony 
with the moist, equable climate, but regulated by the density of the forest- 
roof. Everywhere the effect of that complex of factors, evoked by the forest 
itself, is .manifest in the plant-forms. Shrubs, which in the open would be 
- rounded and symmetrical, put forth long, slender stems, that, liane-like, lean 
against other trees and gain support. Young trees have frequentiy much- 
reduced lateral branches and long, straight, slender main-stems. In some this 
habit is hereditary, and thus the curious juvenile form of Pseudopanaxr crassr. 
folium may be an “adaptation” to the forest-life. 
On the trunks of most of the trees that do not shed their bark in great 
flakes and right up on the highest branches are not only an abundance ol 
true lianes and epiphytes (Plate XXII, Fig. 29), but seedlings of trees and sheoba 
terrestrial ferns of many species and hosts of mosses, liverworts and lichens. 
The trunks of tree-ferns, too, are a favourite station for many plants. Event 
the slender branches of shrubs may be deeply moss-covered, while leaves 
themselves may be the home of various small bryophytes. 
dryer ground than usual, and even then show unmistakably their tropical facies - 
In every type of New Zealand rain-forest the vegetation is in several distinct 
layers, each with a definite light-relation. Where the tallest trees are present, 
ba uppermost Ss ee of their crowns, especially those of the Taxaceae, 
‚ Metrosideros robusta, one or other of the two species 
ölschmiedia tawa, B. tarairi, or species of Nothofagus. Trees 
ofa medium. size form the next layer, while growing, in their crowns, as also 
int those of the upper tier, are me flowering parts of the lianes and the more 
‚epi . — species of Astelia, Griselinia lucida, ‚Pitt porum 
u ic Metrosideros robusta ta). The upper tier does not, as a rule, 
‚the ag relation of these, two ee. tiers is ot 
