360 STATURAL HISTOEY 



found a stream of water, in which most commonly splendid water- 

 cresses abound, along with many beautiful aquatic plants which 

 remain green throughout the year. Among them may be mentioned 

 the celebrated Rapo or Typha augustifolia, which is used by the 

 natives and by new settlers as a convenient building material. 

 They form the walls and roofs of their houses of bunches of it, and 

 tie them together with the Mangi-mangi or climbing fern, Lygedivm 

 articidatum. Very warm and convenient houses are thus constructed, 

 impervious to rain or wind. I have seen the inside lined with cotton, 

 and then covered with figured paper ; and thus finished it is exceed- 

 ingly comfortable, and makes a very respectable appearance. 



The New Zealand flax, Phormium tenax, grows on the margins of 

 the streams, its leaves often measuring six feet in height, surmounted 

 by the flowers on an elevated foot stalk. Its dark green leaves and 

 its tuft-like appearance render it a most graceful object. Again the 

 observer will meet with a cluster of the New Zealand fern tree^ 

 Oyathea medullaris, the noble palm tree, Areca sapida, or the curi- 

 ous grass tree, surmounted by tall luxuriant fgrns. These present a 

 pleasant picture, a combination of grace and beauty not to be sur- 

 passed, I believe, in any other part of the world. 



In the layers of volcanic matter I could easily count three succes- 

 sive streams of lava which are now piled one above the other in wild 

 confusion. These eruptions tended towards the N. E. Towards 

 the N. "W. the expanse of erupted matter is more extended, rugged 

 and broken, but dees not appear to be the result of so many distinct 

 volcanic actions. If the course of the lava current is traced, it 

 sometimes appears to dip, or penetrate the earth for certain distances, 

 again appearing upon the surface. In some instances a smooth dome 

 like surface of the lava will be met with which has cooled without 

 fracture. This presents unmistakeable evidence upon its surface of 

 having flowed slowly, or cooled as it flowed, for marks like wrinkles 

 may be observed, on percussion it sounds hollow, and it has plainly 

 been a spot where the fluid lava was arrested for a short period and 

 its surface cooled, while the internal fluid lava continued its course 

 to the lower levels of the plain. At other points in the same current 

 it may be observed that these domes have given way, and now form 

 deep, rugged and dangerous cavities into which animals sometimes 

 fall, and can seldom get out without assistance, although they may 

 penetrate to some considerable distance along the course of the cur- 

 rent. Some of these cavities contain water, and in many instances 

 they are almost concealed by the thick foliage and beautiful ever- 



