816 ANIMAL HEAT. 
(a) Rabbit placed in dry air 100° — 
Temperature before = 40° 
„ after 5 minutes = 41° 
„ ,,10 „ =44° — respiration quickened. 
„ 16 „ =44°-5- death. 
(b) Head of rabbit placed in dry air 100°, body in cool air — 
Temperature before = 40° 
„ after 5 minutes = 40° 
„ ,, 10 ,, =40° — respiration quickened. 
„ 1-5 „ = 41 °) 
" 9P- ,,. /respiration very rapid. 
55 55 ^" 55 — *" I 
„ 30 „ =43°) 
„ 38 „ =43°— death. 
(c) Body of rabbit in dry air 100°, head in cool air — 
Temperature before =39° "5 
„ after 4 minutes = 42° 
„ ,, 10 ,, =43° — respiration quickened. 
„ 15 „ =44° 
„ 20 „ =45°— death. 
Obernier 1 found that when the external temperature was first 
raised the rectal temperature of dogs and rabbits fell slightly, about 
0°4, but soon after the air reached 30° to 35° the temperature of the 
animal began to rise. Death generally resulted before the internal 
temperature rose to 45°, but in one case it reached 46° "2. The most 
important symptoms were restlessness, quickening of respiration and 
pulse, and finally convulsions and loss of consciousness. A short time 
before death it was impossible to feel the pulse, a fact explained by the 
fibrillar contraction of the heart observed by Obernier when the thorax 
was opened. An examination of the body directly after death showed 
marked congestion of the brain and lungs; the muscles were inexcitable, 
and quickly went into rigor mortis. Similar changes were observed 
in the bodies of soldiers who had died from sunstroke. 
Numerous facts show that cold-blooded animals can live in hot 
media. Thus, internal parasites of mammals and birds can live in sur- 
roundings at temperatures of 37° and 43° - 9; and there are well-authentic- 
ated cases of fishes living in springs as hot as 37°-44°. 2 Sonnerat 3 
even states that he saw fish actively swimming about in the hot water 
(60°-62°) of thermal springs in New Guinea ; it is doubtful, however, 
if the temperature was correctly recorded in this case. 
It has been shown by Davenport and Castle 4 that by gradually 
raising the temperature tadpoles can be kept alive in warm water. 
Hertwig 5 has observed that no development takes place in the ova 
of the frog when the temperature of the water is zero, but between 
2° and 33° it progresses with different rapidity, cold delaying, warmth 
hastening the process. A temperature, however, of 34° is fatal. 
1 "Der Hitzschlag," Bonn, 1S67. 
2 Spallanzani, " Opusc. de phys. anim.," tome i. pp. 54-69, 101 ; Desfontaines, quoted 
from Gavarret, "De la chaleur produite pas les etres vivants," Paris, 1855, p. 464; Tripier, 
Compt. rend. Acad. d. sc, Paris, tome ix. p. 602; Cumberland, Biblioth. univ., Geneve, 
1839, tome xx. p. 204 ; Prinsep, ibid. 
3 " Voyage a la Nouvelle Guine'e," Paris, 1776, pp. 38-41. 
4 Arch. f. Anat. u. EntwcMngsgcsch., Leipzig, 1885, Bd. ii. S. 227. 
6 Sitzungsb. d. iireuss. Akad. d. Wissensch., 1896, S. 105. 
