352 Transactions. 



This connection he attributed to an elevation of the sea-bottom synchronous 

 with an elevation of New Zealand itself, which he postulated in order to 

 explain the extension of the glaciers. It is reasonable to think that in 

 mid-Tertiary times the Chathams were covered by the sea, from the occur- 

 ence of a limestone similar to that of New Zealand with a similar fossil fauna. 

 The form of the land-surface of these islands suggests that subsequentlv 

 they were base-levelled either by the sea or by subaerial agencies. 



Again, Cockayne, in bis paper on the "Plant Covering of the Chatham 

 Islands •" (Trans. N.Z Inst,, vol. 34, 1902, p. 316, footnote), says, "The 

 occurrence on Chatham Island of Coprosma chathamica, so closely related 

 to C. petiolata of the Kermadecs, and of Rhopalostylis baueri in both regions, 

 if the identification of the latter be correct, suggests that they travelled 

 along the coast, which would, in the event of an east and north-east extension 

 of New Zealand, join the Kermadecs and the Chathams." There is good 

 reason, however,, to doubt the occurrence of R. baueri in the Chathams. In 

 the same paper (p. 314. footnote) the author notes the occurrence of SuUonia 

 chathamica at Stewart Island, a plant formerly believed to be restricted 

 to Chatham Island ; but in his report of the botany of Stewart Island the 

 author is very guarded about this occurrence, and considers the possibility 

 of the plant having been introduced by the Maoris, although he thinks 

 this extremely unlikely. If this last contingency is excluded, the 

 Kermadec -Chatham Island coast-line might be prolonged to Stewart Island, 

 following the line of the submarine continental shelf ; but it appears 

 somewhat dangerous to base such a conclusion on the evidence from one 

 or two occurrences of plants unless supported by other lines of evidence. 



The presence of a land in Mesozoic times is rendered probable by the 

 persistent appearance of granitoid and other rocks as boulders in strata 

 of Jurassic age, and later, there being no known occurrence in situ in close 

 proximity to these deposits which could have furnished these boulders. 

 These deposits occur near Gisborne, in beds which are, according to McKay, 

 of Lower Tertiary or Cretaceous age, but, according to Adams, of Upper 

 Miocene age. They occur in Mesozoic strata near Cape Palliser ; at Cheviot ; 

 in the valley of the Acheron and Rakaia Rivers; in the Pudding-stone 

 Valley on the north side of the Rangitata ; in the Malvern Hills; and in 

 various parts of Otago ; and it is probable that they have been shed from 

 a land stretching east which persisted down to Tertiary times. If Adams's 

 determination of the age of the Grisborne deposits is correct, then such a 

 land most probably existed down to the middle of the Cainozoic era, for, 

 as far as is known, the rock pebbles of these beds are not likely to have 

 come from the Trias- Jura ranges to the west, 



The origin of tiie native flora of the country must be considered fully 

 before coming to any conclusion as to the relief of the land. It seems im- 

 possible for the Antarctic element to have established itself or to have main- 

 tained itself in competition with the Malayan element had the high land 

 been completely removed during any part of the Tertiary era, unless there 

 had been adjacent tracts of elevated country, now completely submerged, 

 to which it might have moved as to a sanctuary ; but the difficulty in the 

 way of an invader obtaining a footing seems so great that it appears more 

 likely that an area once peopled has not been subject to great modifications 

 since the colonists obtained a footing. Migrations due to climatic change, 

 or to changes due to the changed elevation of the land, no doubt occur, but 

 very slowly. It seems clear, therefore, that high land must have existed 

 continuously over parts of the South Island, or close to it, since the Antarctic 



