10 Transactions.— Miscellaneous. 
alternately to or from the north, introducing antarctie fauna into the 
northern hemisphere during one cycle, and arctic at another into the 
southern temperate zone. Their respective remains, intermingled at first 
in the upper strata with those of tropical and sub-tropical forms, are now 
being deposited layer upon layer over the beds which contain such different 
ones below, and which will again in many places come to entomb the shells 
and the bones of races similar in type to those which previously there 
. found a grave, when such a change in temperature as has occurred in most 
regions over and over again takes place. 
The most enthusiastic glacialist could ask for no mightier engine than 
the great antarctic stream bearing its vast islands of ice sixty miles and 
more in length far towards the tropics in certain meridians. . 
What local influences are doing now in northern regions, students have 
more ample opportunity of observing. Notably the condition of great part 
of Greenland, where, in latitude 70?, ice islands of enormous dimensions 
float off from a sea-cliff of solid glacier ice 8,000 feet in height. The state 
of things obtaining in that great land may be contrasted with that in the 
equally misnamed country, Iceland, even that of its lower portions in 65? 
N. with that of Lapland in 72°. The climate of the Crimea affords a use- 
ful example when compared with that of Venice or Bordeaux. In conse- 
quence of the radiation from the Thibetan steppes, we find cereals ripening 
on the Siberian side of the Himalaya at a height above the sea equal to 
that of the summit of Mont Blanc, whilst several thousand feet lower down 
arctic cold prevails, and mighty glaciers do their work above the burning 
plains of Hindostan, growing under the soft breath of the rain-bearing 
southerly winds. 
Again intense cold prevails over edidi on the shores of that great 
inlet of the North Pacific which, in not very remote times, teemed with 
animal life of southern types. 
In that region where the Amoor river after flowing amidst lity 
groves and vine-clad hills turns north and enters a frozen sea, a local 
glacial period has possibly commenced, advancing with slow but unwaver- 
ing steps, which might easily be accelerated by the subsidence of the shallow 
sea-bottom which interrupts the flow of polar waters ; whilst in other places 
-owing to a deviation in the direction of local currents of warm and chilled 
waters in seas of no great depth, sub-tropical forms are again multiplying 
where but recently arctic ones usurped possession. 
The iron grasp of frost has loosened its hold over great part of Western 
America, and a temperate climate for ages has been gaining sway over the 
arid regions where rivers flow in deep chasms or canons worn by them 
through the plains under the Rocky Mountains. 
