INFLUENCE OF EXTREME HEAT AND COLD. 
817 
Numerous observations Bhow that the temperature of animals living 
iu the Arctic regions is equal to that of animals of the same classes in 
temperate climates. The following are some of the results obtained by- 
different explorers : — 
Animal. 
Temperature of 
Animal. 
Temperature of 
Air. 
Observer. 
[ 
38°-3 
-35°-6 
Parry and Lyon. 1 
Arctic fox 
1 
1 
41°'l 
-35° -6 
39°-4 
-32° -8 
j 
Wolf . 
40°-5 
-32 = -8 
tt 
AVhite hare 
38^3 
-29° -4 
f 
1 
43 D -2 
-12"' -7 
Black. 2 
Prairie fowl (male) 
43°-0 
-15°-0 
1 
42 3 -8 
-8= -3 
,, 
Prairie fowl (female) 
43 3 '3 
-8°-0 
,, 
1 
42 3> 8 
-1°*1 
,, 
( 
42- -4 
-19°-7 
,, 
Willow grouse (male) 
1 
1 
43- -3 
-32° -8 
,, 
43° -3 
-35° 8 
33 
The limits of extreme cold are generally reached when the water in 
which the animals live, or the lymph of their tissues, is frozen. Fishes 
live in salt water when the temperature is below zero, but usually die 
when the water is frozen. 
Boyle s exposed lampreys in a vessel of water to an exceedingly 
sharp frost, and found next day that one lamprey was frozen in the ice : 
when the ice was partly broken and partly thawed the animal was at first 
motionless, but in a few minutes recovered, and dragged after it a large 
piece of ice in which its tail was fixed. Similar experiments were made 
with similar results upon gudgeons and frogs. Hunter 4 found by 
experiment that the internal temperature of a frog and an eel could be 
reduced to -0 o, 6, and that, although the animals appeared to be dead, 
they revived when the temperature rose. Eegnard 5 found that carp 
will live in water containing 2h per cent, of magnesium sulphate, 
even when the temperature is a degree or two below zero ; at -2° the fish 
appear to be asleep, and at -3° their vitality is so greatly reduced that 
they seem to be dead, but revive when the water is gradually warmed. 
Pictet 6 exhibited at one of his lectures frozen gold fish, pike, and 
frogs, and at the next lecture the same animals alive and well after 
gradual thawing. According to this observer, fishes can be rapidly 
frozen so hard that they can be snapped in two, and yet other fishes 
frozen equally hard recover when slowly thawed. It has been observed 
by Marcet 6 that gold fish completely embedded in the ice showed no 
signs of life on thawing, but one fish, which was partly encased in ice 
and was surrounded by a little water, appeared lifeless, but recovered 
perfectly in a short time. Observations and experiments made by 
1 Parry, "Journal of a Second Voyage for the Discovery of a North- West Passage," 
London, 1S24, p. 157 ; Ann. de chim. et phys., Paris, 1825, Ser. 2, tome xxviii. p. 223. 
2 Compt. rend. Acad. d. sc, Paris, 1836, tome ii. p. 621. 
3 "Philosophical Works," Shaw's edition, vol. i. p. 688. 
4 "Works," Palmer's edition, London, 1837, vol. iv. p. 131 et seq. 
5 Compt. rend. Soc. de biol., Paris, 1895, p. 652. 
6 Quoted from Marcet, Croonian Lectures, Brit. Med. Journ., London, 1895, vol. i. 
p. 1367. 
VOL. I. 
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