152 THE ICK A(;K in t'AXADA. 



ice (lislril)uti(»ii, ])roceP(linjT in tlio Oiivly glacial period 

 from its centre: and later as a series of reefs and islands 

 in the arctic current. 



2. The maritime provinces of Prince Edward Island, 

 Xova Scotia and Xew Brunswick constitute a ])art of the 

 Atlantic slope of North Anunica, and not havin^^ any 

 very hi^h mountains, have had only minor centres of 

 permanent ice, l)ut hiive l)een traversed l)y jtowerful ice- 

 laden currents from the north, and at certain periods of 

 partial submergence, more especially in the later [glacial 

 age, have had boulders scattered over them from local 

 sources in their own hills. I'artsof northern Xew Bruns- 

 wick have been invaded, in the niore extreme glacial ag^, 

 by local glaciers from the north-east extiMision of the 

 Appalachian mountains. 



-S. The Canadian region ])roper, or that constituting 

 the provinces of (,^)uebec and Ontario, includes the wid(! 

 valley of the gulf and river St. liawrence, and part of the 

 plateau of the great lakes. It curses to the south-west 

 and north-west around tlu^ great salient angle of the 

 Laurentian plateau, separating it from the basin of 

 Hudson's bay and the Arctic sea, aiul has to the south- 

 eastward the ridges of tlu; (Jreen and Appalachian 

 mountains forming the breast-bone of the Xorth American 

 continent. In the earlier and more extreme glacial ])eriod 

 its lower lands were suljmerged and received on their 

 margins the ice discharged from the glaciers of the 

 Laurciititle hills, the Adirondacks and the Appalachians. 

 The space Ijetween these now occu])ied l>y the St. 

 Lawrence, was a great channel like P)atlin's bay and Davis 

 strait ; but owing to its direction, nuich more intensely 

 (glaciated bv lioating ice ]>;)rne on the Arctic current, 

 which spread its l)urden over the submerged North 



