248 A. p. COLEMAN TPIE EARLIEST IXTER-GLACIAL PERIOD 



Labrador, cool and wet; but all the plants he mentioned still live in 

 swamps to the north of Toronto and all the trees occair at Toronto. The 

 plants determined from the seeds indicate a climate like the present, as 

 all of them are found here now, and most of them extend much to the 

 south of Toronto. The later evidence just given modifies considerably 

 the conclusion reached by Dootor Macoun, and I am told by botanists 

 that northern forms are often found in peat-bogs or swamps far soutli of 

 their usual habitat. In general, it may be said that the climate of Scar- 

 boro times was distinctly cooler than that of the Don beds and probabl)' 

 somewhat cooler than that of the present, but that it was far remo\e(l 

 from arctic conditions. 



Difficulties of Pkofessoe AVtugiit's Intekpketation 



Prof. G. F. Wright, who has visited the sections at the Don and St-ar- 

 boro, does not accept the interpretation given in the foregoing pages, and 

 suggests another way of accounting for the facts by which the inter- 

 Glacial interval is to be eliminated and the whole series of events is to be 

 condensed into the briefest possible time, apparently a few thousand 

 years. The mechanism by which he would accomplish this is not entirely 

 evident to the present writer, but the following ideas seem to cover the 

 essential points: 



1. The lowest boulder-clay at the Don was not formed by ice from the 

 Labrador center, but by an advance from the Keewatin center to the 

 northwest. This has been shown to be incorrect. 



2. The supposed warm-climate beds, admitted by Professor Wright to 

 imlicate a climate warmer than the present, consist of materials dej)osit('(i 

 in late Tertiary times, transported from somewhere by mysterious nutans 

 and placed gently and deceptively on the lowest boulder-clay. He thinks 

 that the specimens of warm s]iecies of plants and animals may have been 

 '^ploughed up by a readvance of the ice after a temporary recession and 

 raised without much disturbance to the higher beds where they are now 

 found." He supports this view by a reference to the well known but still 

 enigmatic Moel Tryfaen deposits in Wales, where marine shells are sup- 

 posed to have been lifted by the ice and afterward laid down in beds of 

 stratified sand. He says that in a few hours several whole shells could 

 be found, though "most of the specimens are fragmentary." 



Apparently some doubts existed in his mind as to whether the innu- 

 merable whole shells, with no broken frag-ments, and the hundreds of 

 perfectly preserved leaves in the Don beds could have reached their pres- 



