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representatives of the winged insect tribe have been found in the 

 Devonian rocks of Canada. Mr. Crane drew attention to the few 

 but noticeable descendants of the armour-plated fishes of the 

 Devonian, which now exist in some of the seas and rivers of the 

 world, and in connection with this subject, said how much 

 it had been his aim in the arrangement of specimens in the 

 museum to illustrate past forms of life as far as practical by 

 those nearly related to them now in existence. Perhaps 

 the most interesting part of the paper was that which touched on 

 the probable origin of life at the North and South Poles. Among 

 the arguments which the lecturer adduced were the comparative 

 thinness of the earth's crust at the Poles when compared with the 

 -equatorial radius. Assuming, with geologists in general, that 

 the earth was once a molten mass, this difference of 1 3 miles would 

 have favoured the dissipation of heat and consequent cooling at 

 the Poles. Hence the crust of the earth would have been here 

 fitted for life, while the equator would have been still too hot to 

 allow of the development of any organic germs endowed with 

 vitality. Moreover, the heat of the sun at the equator would 

 have further added to the innate heat of the earth in a manner 

 not conducive to the germination of either animal or vegetable 

 existence. Mr. Crane called particular attention to the fact that 

 Polar navigators had brought back evidence as to the different 

 climate which once prevailed at the North Pole. At some 

 epochs in the earth's history life must have been as exuberant 

 there as in what are now the sunny regions of the South. More- 

 over, the great corrugations on the earth's surface, running 

 longitudinally, must have favoured the migration of living beings 

 from North to South, and seemed to point to the fact that life on 

 the earth radiated from there as from its centre and origin. 



