Crawrorp.—On the Old Lake system of New Zealand. 373 
we get the conditions necessary to form the Canterbury Plains into a lake. 
I would suggest that at the period when the islands were united it is 
reasonable to suppose a greater extension of land generally, and perhaps 
particularly to the north-west and south-east of Cook Strait, and the 
east of the South d. 
It will be seen that I agree with Dr. Haast’s view of the lacustrine 
distribution of the gravels of the plains. I hardly think, however, that 
there is a particle of evidence of the former glaciation of New Zealand. 
Glaciation is one thing, glaciers something totally different, and not incon- 
sistent with a climate similar to what now exists. There is any amount of 
evidence of the former further extension of the glaciers of New Zealand; 
but this may have been owing to a greater extension of high, and particularly 
of plateau land, and to depression of the interior of Australia thereby 
extinguishing the cause of heated winds, without calling in the very serious 
change of climate involved in the term “ glaciation.” 
The era in which the Canterbury Plains formed a lake must have 
preceded that of the eruption of Banks Peninsula, as Dr. Haast states — 
that the latter shows none of the gravels of the plains on its surface. 
One point of geological evidence often leads up to another. I have 
previously proved the connection of the islands, and this involves not only 
an elevation, but probably a large extension of land. 
The elevation and extension were probably in two directions. To the 
westward and to the northward of the centre of Cook Strait; to the 
eastward of the South, and perhaps also a part of the North Island. 
During tertiary times New Zealand must have been an archipelago. 
After the deposition of the marine tertiaries the country rose, and in its rise 
appears to have left barriers allowing the formation of large lakes in both 
islands. Subsequent depressions on both sides of the islands at the time of 
the volcanic outbreaks tended to obliterate the barriers of some of the lakes, 
but in the North Island these lakes remained until after the period of the 
great ejection of pumice from the central voleanoes of the Tongariri group, 
which, be it remembered haye been the great pumice producers among the 
New Zealand volcanoes. 
Thus my theory of the connection of the islands, of a Cook Strait 
river, and Port Nicholson having been a fresh water lake, has led in regular 
sequence of argument to a greater elevation of land in Pleistocene times, to 
great extension of lakes in the North Island, and to the conversion of the 
Canterbury Plains into a fresh water lake. Many subsequent changes have 
taken place upon these plains ; but the distribution of the horizontal margin 
of the gravel must, I think, be held to have been effected by the waves and 
and movement of the waters of a large lake. 
