266 JOURNAL OF SCIENCE. 
America there is no evidence as to their date. This is, however, 
unnecessary, for we have already seen that the ancient glaciers 
of New Zealand, of Australia, and of South Africa (if any) belong 
to periods very different from the glacial epoch of Europe. Mr. 
Wallace therefore was hardly justified in assuming, without 
making a persona] examination, that “the close similarity in 
the state of preservation of the ice-marks and the known activity 
of denudation as a destroying agent, forbid the idea that they 
belong to widely separated epochs ;”* and consequently his 
argument that “if we reject the influence of high eccentricity as 
the cause of this almost universal glaciation, we must postulate a 
general elevation of a// these mountains about the same time,}” 
falls to the ground. 
I believe that almost all New Zealand geologists are now 
agreed that our last great glacier epoch was in the pliocene 
period ;{ and it seems that an elevation of the land in pliocene 
times affords the only satisfactory explanation of the phenomena. 
The question now arises, Did the pliocene extension of land-area 
include the outlying islands ? This is a question which has been 
lately much discussed in France. M. Blanchard maintains that 
all were included; M. Alph. Milne Edwards thinks that the 
Chatham Islands only were connected with New Zealand ; and 
Dr. H. Filhol, while allowing a former land extending down to 
the Auckland Islands, doubts whether Campbell Island ever 
formed part of it,§ his reasons being partly geological con- 
siderations which compel him to think that this island only 
appeared above the sea at the close of the pliocene, and partly 
the absence of all land birds and lizards. Mr. Wallace says, 
“whether this early land extended eastward to the Chathams 
and southward to the Macquaries we have no means of ascer- 
taining, but as the intervening sea appears to be not more than 
about 1500 fathoms deep, it is quite possible that such an amount 
of subsidence may have occurred.”|| To try to form an opinion 
of our own we must examine the faunas and floras of these 
islands. 
Chatham Islands.—Distant 400 miles from New Zealand.. 
The fundamental rock of the main island is a micaceous slate,{ 
upon which lie miocene limestone and volcanic rocks. Pitt’s 
Island is composed of volcanic rocks and limestone, with some 
lignite and shale. It is more than 600 feet high, while the main 
island does not attain to that altitude. There appear to be no 
raised beaches or other signs of recent elevation.*, There are 
* Island Life, page 504, 
Tt lc. p. 504. 
t Travers, Trans, N.Z. Inst., VI., p. 302; Dr. von Haast, Geol. of Canterbury, 
p. 372; Dr. Hector, Geol. Reports, 1883, p. 13; 8. H. Cox, Geological Reports, 
1883, p.9. Mr. Dobson alone would put it later, Trans, N.Z, Institute, VII., p. 
oO. 
§ See Bed ree of Science, I,, pp. 251 and 259. 
|| Island Life, p. 455. 
¥. Haast, Trans. N.Z. Inst., I., p, 180. 
* Travers, Trans, N.Z. Inst., [V., p. 63. 
