390 T7-ansactions . — Geology. 



only filled the channel, but had in places destroyed the trees 

 which stand on the jagged banks. Most of the trees for a 

 chain or so on either side of the channel had their leaves 

 blackened, or reddened, or browned, as if they had been sud- 

 denly scalded by hot water, or the roots of the trees had 

 been killed by hot water, the leaves remaining on the trees 

 to brown and die. The material ejected from Te Mari on 

 this side of the mountain was strongly impregnated with 

 alum, and the water in the small water-holes at the base of 

 every rocky face was very bitter and undrinkable, although as 

 clear as crystal. The discoloration, and thereby the destruc- 

 tion, of the forest leaves in this way was to me of special 

 interest in its suggestiveness, and I felt amply repaid for my 

 trouble by the new light such an objective example threw 

 upon a difficulty which had presented itself to me for some 

 time in connection with the deposition of fossil leaves, &c. 

 For several years I have occupied myself at intervals of 

 leisure in collecting impressions of leaves, fishes, &c., from the 

 Poverty Bay and Kidnapper Post-pliocene deposits. Some of 

 the principal beds of the series are made up of a fine pumice, 

 interbedded with a kind of pumice-mud, in which there are 

 beautiful impressions of the forest flora — leaves, flowers, and 

 ferns — of this country, mixed with impressions of fresh- water 

 fishes (koura ?) and other traces of animal life. From the 

 appearances represented by the leaves on the scalded trees, I 

 am of the opinion that this mode of destruction explains and 

 illustrates the manner in which the leaves in the Poverty Bay 

 and similar beds vv'ere destroyed and subsequently deposited 

 in a lake or estuary. The impressions on the pumice-mud are 

 raised like the impress on a coin, and they show" each vein 

 and veinlet and all the surface irregularities such as appear on 

 a green leaf. Such impressions, it seems to me, could only 

 be made in the case of leaves whose growth had been sud- 

 denly stopped and destroyed without injuring the leaves. No 

 doubt the reddened, browned, and blackened leaves from the 

 dying or scalded trees on Tongariro will be carried into Lake 

 Eotoaira, or, maybe, into Lake Taupo, and there deposited 

 with the fine pumice-mud which is constantly flowing into 

 these lakes from the numerous streams and springs in the 

 vicinity of Tongariro. 



Beyond the belt of bush and scrub there is little or no 

 vegetation on the mountain. A few scattered plants were 

 gathered, such as gentian, Sophora, Cehnisia spectabilis, An- 

 gelica, Ranunculus, a sweet-scented Pimelea, a Claytonia, and 

 a Hector clla. 



On reaching the old crater which adjoins Te Mari, and to 

 which reference has already been made, the extent of the 

 eruption could be plainly seen. The mountain, extending 



