INTELLIGENCE, POWER, 



weighed 620 pounds. It was too large to hoist from its tomb, 

 so we dissected it where it lay. The bearded seal is the largest 

 of all northern seals and is more or less solitary in its habits. 

 Its skin is thicker than that of any other northern seal and 

 is much valued by the Eskimos. The bearded seal, like the 

 walrus, feeds on mollusks and crustaceans. The ring seal is 

 a fish eater. 



When we reached Morso Island, a walrus hunt was in 

 progress. The Eskimos, with long, curved knives, worked 

 with incredible speed. 



In contrast to animals in the equatorial regions, the 

 walrus, a warm-blooded mammal living in the cold sea, 

 had a thyroid gland much larger than the adrenal glands. 



In our studies of the energy-controlling organs of animals 

 in tropical Africa and of animals in the arctic, we found 

 definite evidence of the influence of cold and of heat alone 

 upon the size of the energy-controlling organs of warm- 

 blooded animals. Temperature alone in the arctic requires a 

 larger brain, a larger heart and blood volume, and a larger 

 thyroid gland to execute the oxidation necessary to main- 

 tain the warm-blooded state. The influence of habitat tem- 

 perature is clearly seen in the case of the walrus that we 

 secured in the arctic. 



In the case of the rhinoceros secured in equatorial 

 Africa, the opposite is seen, for, because of the ceiling of 

 heatstroke, the influence of tropical temperature is toward 

 a smaller brain and a smaller thyroid gland. 



The second basic influence seen in the comparison of the 



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