816 ANIMAL HEAT. 



(a) Kabbit placed in dry air 100 



Temperature before = 40 



after 5 minutes = 41 



10 =44 respiration quickened. 



16 = 44'5- death. 



(&) Head of rabbit placed in dry air 100, body in cool air 

 Temperature before = 40 



after 5 minutes = 40 



,, 10 =40 respiration quickened. 



15 



20 

 25 



30 

 38 



= 41 



= . ,. 



43 i res P ira ^ lon ver J 







- 43 death. 



(c) Body of rabbit in dry air 100, head in cool air 

 Temperature before = 3 9 '5 



after 4 minutes = 42 



10 =43 respiration quickened. 



15 44. 



J) }) **r 5) "~ ** 



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 0< 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, 1867. 



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 Guinee," Paris, 1776, pp. 38-41. 



4 Arch.f. Anat. u. Entwcklngsgesch., Leipzig, 1885, Bd. ii. S. 227. 



5 Sitzungsb. d. preuss. Akad. d. Wissensch., 1896, S. 105. 



