262 JOURNAL OF SCIENCE. 
rated by a strait only 500 feet deep, the difference between their 
floras and faunas is far greater than the difference between the 
floras and faunas of England and Europe which were separated 
in the pleistocene period immediately after the glacial epoch. 
In the South Island we have six different kinds of birds repre- 
sented by different species in the North Island,* and this cannot 
be due to difference of climate, because some parts of the South 
Island are further north than parts of the North Island. Of the 
plants I am not competent to speak, but a comparison of the 
floras on each side of Cook’s Strait would be of great interest.t+ 
Consequently the two islands of New Zealand must have been 
separated during, at least, the whole of the pleistocene period. 
But an elevation of 500 feet would join them, and an elevation 
of 1100 feet would lay bare the whole of Cook’s Strait, so that 
we are driven to the conclusion that this amount of elevation has 
not occured during the pleistocene period, and consequently our 
glacier epoch must have been earlier than the European glacial 
epoch. On the other hand the similarity of the land shells, in- 
sects, plants, birds, &c., forbids us placing the last separation be- 
fore the pliocene. That is to say, New Zealand must have stood 
more than 500 feet higher than at present during some part of 
the pliocene period ; for, if not, the plants and animals on the two 
islands would have been more differentiated than they are. 
But even if we do not assume that elevation was the cause of 
our glaciers, still there is independent evidence that our glacier 
epoch is older than the glacial epoch of Europe and N. America. 
First there are the glacier phenomena themselves. Several of 
the older lakes, such as those of the Rakaia, and of the central 
parts of Otago, have been completely filled up ; while others, such 
as the lake in the Upper Dillon, Lake Heron, Lake Tekapo, and 
Lake Pukaki, are approaching their end. Glacier striz are 
generally absent, although the rocks still retain their rounded 
form ; and in the district of Central Otago masses of rock ten or , 
twelve feet in thickness have been removed from the mountains 
by ordinary atmospheric weathering since the ice passed over 
them.t In the second place the drainage system has been much 
altered since the glacier epoch; the gorges of the Kawarau, 
Dunstan, Mataura, and Upper Taieri in Otago,§ and that of 
the South Ashburton in Canterbury, having been entirely cut 
since then. 
* SouTH ISLAND. Nortu IsLanp, 
Myiomoira macrocephala represented by M. toitoi. 
Myioscopus albifrons Fr M. longipes. 
Turnagra crassirostris is T. hectori. 
Glaucopis cinerea ae G. wilsoni., 
Ocydromus australis sf O, earli, 
Apteryx australis A. mantelli, 
> 
t In the Titans, N. Z. Inst., XVI, p. 466, Mr. W. T. L. Travers gives an in- 
teresting table shewing the distribution between the islands of 16 genera of plants ; 
but as no attempt is made to distinguish the differences due to different station and 
climate from those due to isolation, it is not available for my present purpose. 
+ Geology of Otago, p. 91. 
§ Geology of Otago, p. 94. 
