80 Proceedings. 



From Lake Superior westward for 200 to 300 miles is a deso- 

 late region with a vast number of lakes, swamps, and pools, 

 perhaps as many sheets of water as in all the world besides. 

 The forest-trees become finer, and a purely American flora 

 appears. This flora is characterised by a great number of 

 Ericaceous shrubs, such as Kalmias, Ledums, Andromedas, 

 and the great Cranberry, Vaccinium macrocarpum. Another 

 prostrate shrub that abounds is Chiogenes hispidula, the Snow- 

 berry. In the wetter parts Saracenia imrpurea is found ; it is 

 a carnivorous plant with a pitcher-like leaf, the upper part of 

 which is hairless and glabrous, the interior being covered with 

 hairs that prevent the egress of insects that fall into it ; its 

 seeds are remarkable, with a large, flat, tabular, persistent 

 style. Two plants abound that are very scarce in Great 

 Britain, Isnardia palustris and Jimcus tenuis. 



The region of the Great Lakes is volcanic, and their drainage 

 area very small, the watershed hugging Lake Superior. This 

 gives rise to the question as to how the water system is fed, 

 the outflow of the St. Lawrence being of great volume. It 

 seems probable that the lakes must be fed by subterranean 

 volcanic channels, and this theory is confirmed by the fact 

 that the temperature of Lake Superior scarcely varies summer 

 or winter from 40° Fahr. 



To the west of the Swamp region the prau-ies begin to be 

 watered by rivers flowing N. or N.E. Here are aUuvial de- 

 posits with underlying Cretaceous rocks, the alluvial soil giving 

 its immense richness to Manitoba. Though practically level 

 for hundreds of miles, there are three steps in the Prairies, 

 and three separate drainage systems of the Eed Eiver, and 

 North and South Saskatchewan. 



Between the main drainage districts are several small areas 

 without any outlets, the streams losing themselves in lakes, 

 which are consequently salt. The vegetation immediately 

 surrounding the pools is destroyed by saline evaporations, 

 and the district, from the aromatic character and silvery-grey 

 foliage of the plants, is known as the " Sage Scrub." These 

 plants are of many genera, but all have the same general 

 character of foliage. 



The Prairies are from lOOU to 1500 ft. above the sea-level. 



