Cockayne. — Butaaical Excursion to Houtliern Inlands. 2i7 



longifolmm. The forest-roof, as before described, is of ex- 

 treme density, and it is situated some 4-5m. above the sur- 

 face of the ground. Such a dense covering, combined with 

 the great amount of moisture in the atmosphere, aifords 

 very strong hygrophytic conditions within the forest, with tlie 

 result that plants of the most marked hygrophytic structure 

 abound, and grow with great luxuriance. The forest floor is 

 extremely uneven. Large mounds, formed in part of decayed 

 vegetation, consisting principally of mosses and liverworts, are 

 very common. Such mounds, the forest-floor in general, and 

 the many fallen and dead tree-trunks are densely covered with 

 liverworts, mosses, and filmy ferns, the two former frequently 

 forming great cushions. These same plants are also epiphytic 

 on the tree-trunks and stout spreading branches of the rata, 

 forming finally, in many cases, deep masses of soil, in which 

 seedling trees and shrubs grow with vigour. Hymenophylknn 

 multifidiwo and several other filmy ferns form sheets on the 

 bark of the trees, while Polypodium bUlardieri, one of the most 

 characteristic plants of this forest, climbs over their trunks, 

 and also ramifies over large areas of the forest-floor. Fre- 

 quently this latter is quite occupied by an extremely dense and 

 deep undergrowth of Aspidvum vestdum, or, nearer the shore, 

 there is much Asplenium ohtusatuvi and Lomaria dura. In 

 other places the ferns may be replaced almost altogether by a 

 still denser undergrowth of Suttonia divaricata, so close that 

 the shrubs touch one another. In such places as this, but for 

 the seals' tracks and what I took to be pigs' tracks higher up, 

 but which may also be made by seals, progress through the 

 forest would be much more difficult. 



If we consider the climatic and edaphic conditions to which 

 the rata formation is subjected we find them extremely di- 

 verse. There is on the one hand the almost constant wind, 

 which very frequently assumes the character of a furious gale 

 — a strongly marked xerophytic factor. There is also a very 

 wet, badly drained, peaty soil — a soil, indeed, probably to 

 some extent physiologically dry — a second xerophytic factor. 

 But on the other hand is a climatic condition diametrically 

 opposite to the above, one strongly hygrophytic indeed — 

 namely, an extremely moist and equable climate, which fa- 

 vours forest-growth exceedingly, and would be an ideal rain- 

 forest climate (92, p. 505) were the mean summer temperature 

 not so low. 'The physiognomy and interior contents of the 

 forest is the resultant of these opposing factors. Thus, there 

 is every indication of the mechanical action of the wind on 

 the trees causing the flat dense roof of foliage and gnarled 

 trunks and branches ; but the moist climate at the same time 

 encourages the spread of the forest as a whole, and the 

 luxuriant lateral growth of the branches, which is out of all 



