428 MR. r. W. HAEMER 0]S^ THE [Aug. I9OI, 



America, moreover, may possibly have been cold at all stages of 

 the Glacial Period : even when the ice-sheet began to break up, 

 masses of melting ice would continue to exist in different districts, 

 so that a cold, and more or less ice- clad area, shrunken indeed in 

 •extent, might have persisted in the north-west, possibly for a long 

 time/ While this lasted, the relative positions and the alignment 

 of the areas of high and low pressure over the region near Behring 

 Strait, and the direction of the winds resulting, might not have been 

 greatly changed. The time would have come, however, when the 

 influence of the anticyclone of the jS^orth American ice-sheet, or of 

 what remained of it, was no longer strong enough to keep the 

 Eehring Strait cyclone in the position which I suggest it may have 

 prevalently occupied during the Mammoth Period. It would have 

 eventually swung round to the statistical position that it now occupies, 

 the climate would have become colder, perhaps more or less suddenly, 

 killing off the forests and the elephants alike, possibly during the first 

 winter.^ Sir Henrj^ Howorth insists strongly on the sudden dis- 

 appearance of the mammoth, attributing it to floods. Prof. James 

 Geikie suggests the frequent occurrence of blizzards. The third 

 hypothesis, however, that the sudden extermination of mammalian 

 life in this region was due to such a meteorological cause as that here 

 suggested is at least conceivable. 



The climate of Alaska during the Pleistocene Epoch seems to have 

 been always milder than that of other parts of North America. 

 There is no evidence of extensive glaciation in that country, but 

 seeing that it forms a peninsula, surrounded on all sides but one by 

 the sea, this cannot have been due to any deficiency of moisture. A 

 distribution of pressure during the glaciation of North America such 

 as that shown in fig. 18 (p. 452) would have brought southerly 

 winds over Alaska, and have prevented any permanent accumulation 

 of snow in the latter country as far as their influence extended. The 

 absence of traces of glaciation in that part of North America which 

 lies west of the Missouri may have also been due to a similar 

 cause. 



Some such meteorological conditions as those now existing may 

 have prevailed in the North Pacific area as far back even as the 

 Miocene Epoch. Mr. P. F. Kendall has kindly reminded me that 

 the Miocene floras of Kamtchatka and Japan are of a comparatively 



^ Prof. Ohamberhn remarks that ' no one probably doubts the persistence 

 of glaciation [during the Pleistocene Epoch] on the heights of the Cordil- 

 leras or in Greenland': quoted in Geikie's 'Great Ice Age' 3rd ed. (1894) 

 p. 772. There does not seem to be any meteorological difficulty in supposing 

 that the ice may have been to some extent permanent in the region west of 

 Hudson Bay, even at the time when milder couditions were prevailing near 

 Toronto. 



- South-easterly winds could only have prevailed in the Liakof Islands 

 during winter, while the isobars ran in a south-easterly and north-westerly 

 direction; and this could hardly have occurred, unless the centre of the 

 North American anticyclone occupied some such position as that shown in 

 fig. 18 (p. 452). 



