i 877-J Southern Hemisphere . 345 
Polar ocean abound with them, and that they occur in 
such myriads that where washed on the bergs or pack-ice 
by the sea they stain it a pale ochreous colour. These 
remains were detected along every ice-bound shore, and in 
the depths of the adjoining ocean between 80 and 400 
fathoms.* Nor is life in the polar regions restricted to these 
minute organisms, for recent ArCtic explorations have proved 
that mollusks and crustaceans swarm at the very foot of the 
Greenland glaciers, and even to the north of Siberia where 
the water is freshened by the great floods, poured into the 
ArCtic Ocean by the Obi and the Yenisei. 
In New Zealand, Mr. Crawfurd has recognised the signi- 
ficance of the absence of marine life in the deposits form- 
ing the plains, and has suggested that they have been 
spread out in great fresh-water lakes. To account for the 
origin of these lakes he supposes that there was formerly 
a barrier of land running down the south-eastern coast, 
which has since entirely disappeared. f Agreeing as I do 
with Mr. Crawfurd, that the faCbs he has brought forward 
show that these deposits are not marine, it is difficult to 
believe in the possibility of a ridge of land having been 
elevated, since Pliocene times, along the whole coast of New 
Zealand, to a height of 2000 feet, and utterly destroyed 
since, so that not a vestige of it remains. 
It will have been premised that I attribute the origin of 
these deposits, as I have those of similar ones in South 
America, to the advance of the Antarctic ice upon the coast 
so as to block up the drainage of the land. The great 
feature of the Glacial period is, of course, the enormous de- 
velopment and accretion of ice, and to call in its aid appears 
less hazardous than to invoke oscillations of the earth’s 
crust, which, in our present ignorance of the condition of the 
interior, may be impossible. I do not hide from myself the 
vast quantity of ice that is required on this supposition ; nor 
the difficulty of accounting for its formation, and I have only 
been driven very gradually and unwillingly to the conclusions 
I now hold respecting its extent. In my last paper in this 
Journal I endeavoured to show that in the North Atlantic 
area the ice would accumulate most at the northern end of 
that great evaporating basin ; that when it was heaped up 
on Greenland to such a height as to intercept all the mois- 
ture of the currents of air travelling northwards, the pre- 
cipitation would take place on its southern slope only ; and 
* Flora Antarctica, vol. ii., p. 503. 
f Trans. New Zeal. Inst., vol.^viii., p. 369, 
