ANIMAL HEAT 383 



they were never frost-bitten, and never had a cough or cold. 

 Exposure to a low temperature renders the body sensitive to a 

 rise in the thermometer. Jackson, in the work previously noted, 

 tells us that the July temperature of 8° above freezing-point 

 made it feel like midsummer, and far too warm ! Conversely, 

 living in a high temperature renders the body very sensitive to a 

 fall in the thermometer. 



If a part be persistently protected against air-currents, it 

 becomes sensitive to exposure ; if it be habitually exposed, a 

 considerable degree of cold can be borne with impunity. Our 

 faces are never covered, and only the hands by some. People 

 who wear no gloves do not complain of cold hands, and it takes a 

 winter of Arctic intensity to make the face feel cold. Women 

 naturally wear far less clothing than men, and in consequence, 

 under the necessities of fashion, they exhibit a remarkable 

 degree of tolerance to cold. The bare-footed child is not 

 conscious of cold feet, nor is he, or the hatless man, marked out 

 as a subject for catarrh. We have the evidence of Darwin* 

 that unclothed man can withstand the most tempestuous climate 

 in the world outside the Arctic Circle. The natives of Tierra del 

 Fuego at the time of Darwin's visit wore nothing ; newly-born 

 infants were exposed like their parents. These people did not die 

 from cold, in spite of the rigours of the climate ; their heat-regu- 

 lating mechanisms were evidently perfect. 



Clipping. — Now that the clipping of horses can be done expedi- 

 tiously and cheaply, fashion decrees that the horse shall be clipped 

 all over. Limited clipping is absolutely necessary for working 

 horses, but there is no necessity to remove all the hair of the body. 

 Strange to say that when this is done horses do not feel the effects 

 of being robbed of their natural cover, even though no clothing be 

 supplied. After twenty-four hours they do not feel the cold any 

 more than a man does who has had his hair closely cut ; neverthe- 

 less, they are losing, in consequence, more heat, and therefore 

 require more food. It is economical to clothe the horse which is 

 wholly clipped. Siedamgrotzky observed the effect of clipping on 

 the temperature of horses. He found that the temperature rose 

 after the operation, and fell to normal about the fifth day. It 

 was observed that clipped horses had during exercise a higher 

 rectal temperature by 1-8° F. than undipped horses, and the 

 return to normal was more steady and regular with them than 

 with undipped. The rise in temperature after clipping may be 

 due to vasomotor action ; less blood being in the skin, more will 

 find its way to the viscera — viz., to parts of the body which have 

 a naturally high temperature., the result being that the total mass 

 of blood has its temperature raised. Another way of accounting 

 * ' Voyages of the Adventurer and Beagle.' 



