HUMAN FACIAL RESPONSES 



all subjects. The blood flow values reported in this study are con- 

 siderably higher than those reported by Brown et al. (1952); these 

 authors suggest that Brown kept his subjects cooler, and their hand 

 flows were influenced by vasoconstrictor fiber activity. During im- 

 mersion in G water the temperatures of the cold habituated sub- 

 jects (Lapps and fishermen) were similar to those of the controls. 

 There was, however, an earlier onset of vasodilation in the Lapps 

 and fishermen. Although the cold habituated subjects experienced 

 less pain and discomfort, two Lapps and three fishermen fainted 

 during the experiment. The results of the study did not support the 

 hypothesis that cold habituated individuals possess a purely local 

 vascular adaptation resulting in a greater blood flow through the 

 hands . 



Lapp summary . Kautokeino Lapps, when compared with Nor- 

 wegian controls, slept well with no obvious shivering during a night 

 exposed to an air temperature of C and lost more heat from the 

 core because of a lower metabolic heat production (Lange Andersen 

 et al., 1960). Paradoxically, the criticaltemperature is the same for 

 Lapps and Norwegian controls (Scholander et al., 1957). Hand blood 

 flows at various temperatures and finger temperatures inO C water 

 are the same for cold habituated nomadic Lapps, Lofoten Island fish- 

 ermen, and controls, but the former two groups vasodilated earlier 

 and reported less pain when vasoconstricted. 



The Indians of Southern Chile 



The aboriginal inhabitants of the islands in and around the 

 Straits of Magellan in southern Chile and Argentina became famous 

 for their cold hardiness through the writings of Charles Darwin, who 

 visited this region in the H. M. S. Beagle. The Fuegian tribes con- 

 sisted of the Chono, Haush, Ona, Vaghan, and Alacaluf, Only the 

 physiology of the Alacalufs has been investigated. 



The Alacalufs formerly inhabited the islands from the Gulf of 

 Penas as far south as the northwest part of Isla Grande on Tierra 

 del Fuego. This habitat is an isolated and densely vegetated region 



347 



