WARM-BLOODED ANIMALS. 



711 



is very minute, and rises with the temperature, until at 34 the output 

 is, weight for weight of body, equal to that of a man. 



The observations of Pembrey l and Vernon 2 seem to show that the 

 output of carbon dioxide in frogs (Rana temporia) does not increase in 

 exact proportion with the temperature. 



Warm-blooded animals. Since the first experiments by Crawford, 3 

 in which it was shown that a guinea-pig produced more carbon dioxide 

 in cold than in warm surroundings, numerous observations 4 have been 



1 " Proc. Physiol. Soc.," Journ. PhysioL, Cambridge and London, 1894, vol. xvi. 



2 Journ. PhysioL, Cambridge and London, 1894-1895, vol. xvii. p. 277. 



3 " On Animal Heat," London, 1788, pp. 311, 387. 



4 Delaroche, Journ. de phys. de chim. etc., Paris, 1813, tome Ixxvii. p. 5 ; Vierordt, 

 "Physiol. des Athmens," 1845; Wagner's "Handworterbuch," 1844, Bd. ii. S. 828; 

 Letellier, Ann. de chim. et phys., Paris, 1845, Se"r. 3, tome xiii. p. 478 ; Lehmann, AbhandL 

 d. k. sacJis. Gesellsch. d. Wissensch., Leipzig, 1846, S. 463; Liebermeister, Deutsches Arch, 

 f. Idin. Med., Leipzig, 1872, Bd. x. S. 89, 420 ; Gildemeister, Virchow's Archiv, Bd. Hi. 

 S. 130; Sanders-Ezn, Ber. d. k. sdclis. Gesellsch. d. Wissensch. Math. -phys. CL, Leipzig, 

 1867, S. 58 ; Rohrig and Zuntz, Arch. f. d. ges. PhysioL, Bonn, 1871, Bd. iv. S. 57 ; 

 Pfliiger, ibid., 1876, Bd. xii. S. 282; Regnault and Reiset, Ann. d. Chem. u. Pharm., 

 1850, Bd. Ixxiii. S. 260 ; Berthollet, Mem. de la Soc. de phys. et de chim. d'Arcueil, Paris, 

 tome ii. ; Senator, Arch. f. AnaL, PhysioL, u. wissensch. Med., 1872, S. 1 ; 1874, S. 42, 

 54 ; Centralbl.f. d. med. Wissensch., Berlin, 1871, Nos. 47 and 48 ; Erler, Arch. f. Anat., 

 physiol., u. loissensch. Med., 1876, S. 556 ; Litten, Virchow's Archiv, 1877, Bd. Ixx. S. 10 ; 

 Fredericq. Arch, de bioL, Gand, 1882, tome iii. pp. 736, 743; Quinquand, Compt. rend. 

 Acad. d.'sc., Paris, 1887, tome civ. p. 1542. 



5 Arch. f. d. ges. PhysioL, Bonn, 1877, Bd. xiv. S. 92. See also Pfliiger, ibid., 

 S. 469. 



6 Ibid., 1877, Bd. xv. S. 603. 



7 Arch. ital. de bioL, Turin, 1891, vol. xv. p. 223. 



8 Arch, de bioL, Gand, 1887, tome vii. p. 265. 



9 Ztschr.f. BioL, Miinchen, 1878, Bd. xiv. S. 51. 



