124 THE GLACIER EPOCH OF AUSTRALASIA. 
Northern and Southern Hemispheres. Whatever grounds 
there may be for this view, it is clear, from the absence of 
huge ice-borne erratics, and other evidences on the lower levels, 
we are not justified in assuming a very serious and general 
refrigeration of the climate in the Australasian regions.” 
“That a considerable change of climate, however, had its 
beginning at this time is most probable, as evidenced by the 
sudden disappearance of the characteristic flora of the older, 
or Paleogene, epoch; and especially by the striking contrast 
which its unstratified, irregular drift deposits (almost barren 
of all traces of life) present, as compared with the more 
regularly stratified members, replete with life remains, of the 
Paleogone epoch.” Again, in discussing the causes of colder 
climate, pp. 254-257, I stated, “‘ It is clear that the conditions 
under which the successive, irregular, coarse, shingly terrace 
drifts had been formed in the main valleys were very 
different from those under which the Paleogene formations 
were deposited, and it is also probable, as suggested in respect 
of equivalent formations in New South Wales by Mr. S. 
Wilkinson, and in South Australia by Professor Tate, that 
the mode of deposition and other circumstances indicate a 
greater rainfall than at present. The paucity of life in the 
formations by itself, while depriving us of the aid of palzon- 
tology in the classification of the rocks and in inferring 
local climatic conditions, only affords negative evidence in 
support of a growing refrigeration of climate. Whether 
this supposed change in the direction of a _ colder 
climate became sufficiently intense within the period to pro- 
duce the local ice sheets and glaciers, of which there is 
evidence in valleys of the western highlands of Tasmania, 
notably along the deeply cut ravines of the Mackintosh 
River, it is difficult to determine. It is quite con- 
ceivable, however, that simultaneously with the rising 
of;the floor of the old Paleogene sea the adjacent land par- 
took of a corresponding elevation ’’—(and to this we may now 
add the conception of maximum eccentricity of the earth’s 
orbit, whose occurrence is placed about 550,000 years before 
the glacial epoch by Dr. Croll, which time would approxi- 
mate closely to the early part of our Neogene period or begin- 
ning of our pluvial epoch)—“ and we may therefore expect to 
find, as a direct consequence, a considerable change of tem- 
perature over the area so affected.” 
It is important also to observe, here, that Prof. Hutton is of 
opinion that the former greater extension of the New Zealand 
glaciers occurred during the interval between the Pareora 
system and the marine beds of the Wanganui system, z.., 
at a period isochronous with our Neogene pluvial drifts and 
terraces. 
