216 ANIMALS AT WORK AND PL A Y 



of liquid fire. One would have thought Arctic life 

 must cease, because, even if possible, it was not worth 

 living ; that there would be a voluntary exodus of 

 beasts, as of birds, before the winter setting of the 

 sun ; and the slower-moving mammals would go, to 

 return no more. 



Yet in the deep seas the inconceivable has been 

 found to exist ; highly organised creatures live and 

 are reproduced where no light penetrates, where no 

 plants grow, in eternal cold, and in a pressure twenty 

 times greater than that which drives a railway train ; 

 and in the Arctic circle mammalian animals, birds and 

 plants endure a five months' night, and a temperature 

 far lower than that of the deep seas. The lowest 

 temperature of the ocean abyss was found to be 

 29 Fahr. below freezing point. That of the 'Polar' 

 night falls from 70 to 90. The cold endured by the 

 Arctic animals is almost as astonishing as the pressure 

 borne by the creatures of the deep sea ; yet in 

 neither is there any notable change in structure to 

 meet these conditions. The Arctic mammals do not 

 differ greatly from those of kindred species found 

 elsewhere. Why, then, do they stay where they 

 are? And how do they continue to endure the 

 plague of darkness and the desperate cold? 



The problem is explained in part by Mr A. 

 Trevor-Battye, in a suggestive and well-written paper, 



