INTELLIGENCE, POWER, 



1:619, an d the ratio of the weight 

 of the brain and thyroid gland to the 

 body weight of Nureddin, the famous 

 Arabian stallion, was 1:694. 



In our expedition to the subarctic 

 region we studied the ratio of the 

 energy system to the body weight of 

 the caribou, the wolf, the husky dog, 

 the hare, the fox, the lemming, the 

 mouse, as well as of the Eskimo 

 himself. We wished to learn whether 

 in the cold north wild animals and 

 man require a greater rate of oxida- 

 tion to maintain the warm-blooded 

 state, as shown by a higher ratio of 

 the weight of the brain and of the 

 thyroid gland to the body weight, 

 than is shown in man and compara- 

 ble animals in the temperate and the 

 tropical zones. This we found to be 

 the case. 



It would seem, therefore, that the 

 factors contributed to the thorough- 

 bred horse by the mares of the cold 

 north were a larger brain, a larger 

 heart, a greater volume of blood and 

 a larger thyroid gland than were 

 possessed by the desert stallion, such 

 as the Arab, the Barb, and the Turk, 

 to which these native mares in Brit- 

 ain were bred. 



Dr. McKay has shown that the 

 rather abrupt appearance of this 

 new type of horse was seen in 

 Matchem, Herod, and Eclipse, in a 

 period ranging from 1748 to 1764, 



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