THE VEGETATION OF WHITE ISLAND, NEW ZEALAND. 41 
The Vegetation of White Island, New Zealand. By W. R. B. OLIVER. 
(Communicated by L. COCKAYNE, F.R.S., F.L.S.) 
(PLATES 2 & 3, and 2 Text-figures.) 
[ Read 6th February, 1914.] 
THE plant formations of White Island are of interest, as they exist under 
conditions scarcely paralleled elsewhere in the New Zealand region, namely, 
in the presence of fumes of hydrochloric acid. The voleano is in the 
solfatara stage and discharges from its crater immense quantities of steam : 
hence the name, White Island, bestowed on it by Captain Cook. It is a 
small cone, 48 km. from the nearest point on the mainland, and being 
surrounded by water 330m. in depth, and of comparatively recent origin, 
it is probable that it has never been united to the mainland and has therefore 
received its plants by accidental dispersal. In extreme length it is 
2*4 km., and its highest point, according to the Admiralty chart, is 328 m. 
Viewed from the sea, White Island is a magnificent sight. The outer 
slopes of the crater are coloured pink, and have at their base and western 
end dark green patches of vegetation. From the south a portion of the 
sulphur-coloured cliffs within the crater is seen near the eastern end, while 
apparently from the top of the island issue immense columns of steam, which 
in fine weather rests as a white cloud above. On landing, one is faced by a 
gorgeous panorama formed by the precipitous inner walls of the crater. It 
is a veritable inferno, and саге must be taken in exploring the erater floor, 
as all the steam, which escapes from innumerable fissures, is more or less 
charged with poisonous fumes. The cliffs are rather brightly coloured, yellow 
and red tints prevailing. А lake of greenish-yellow water, boiling in many 
places, stretches across from cliff to cliff (see Plate 2). From it rise clouds 
of greenish-yellow steam, which is of a partieularly harmful nature, as it is 
heavily charged with hydrochloric acid fumes. Beyond the lake, from 
many blow-holes, there ascend huge columns of steam, which on reaching 
the erater-rim some 300 m. above are usually carried away by the wind. 
White Island is composed of lava-tuffs with few streams of lava inter- 
stratified, sloping at a steep angle, about 25?, from a central crater, the inner 
walls of which are precipitous, but are broken away almost to sea-level at 
the eastern end. The tuffs consist of fragments of lava-rocks of various sizes 
loosely held together by finer material. The whole readily breaks down and 
crumbles away under the action of the weather. The outer slopes of the 
crater are therefore very steep, difficult and dangerous to walk over, as the 
stones give way at every step, and are deeply furrowed by innumerable 
channels often impassable on aecount of their precipitous sides of loose 
