804 ANIMAL HEAT. 



temperature of the air. Newly-born guinea-pigs, however, were able 

 to maintain their temperature, provided that the exposure to cold was 

 not very great. Edwards therefore divided the young warm-blooded 

 animals into two classes, the warm-blooded and the cold-blooded. In 

 the former class the young animals are at birth blind, helpless, in some 

 cases naked, and cannot maintain their temperature. The members of 

 the latter class are even at birth in a condition of great development ; 

 their eyes are open, they are active, and maintain a fairly constant 

 temperature. It was also found that young birds could be classified 

 in a similar manner. As the animal grows, the fall in temperature on 

 exposure becomes less and less, and about the fifteenth day after birth 

 a fairly constant temperature can be maintained. 



Edwards showed by comparative Experiments that the fall in tem- 

 perature on the exposure of newly-born animals was not due to the 

 greater cutaneous surface, in proportion to the mass of the body, as com- 

 pared with the ratio in adults. The absence or presence of feathers or 

 fur was only of secondary import, for an adult sparrow was able to 

 maintain its temperature even after all its feathers had been plucked 

 out. 



Kaudnitz 1 in 1888 discussed very fully the temperature of infants. 

 He made observations upon the variations of temperature in infants at 

 birth and during the first few days after birth. The influence of the 

 large cutaneous surface in relation to the mass of the body, and the loss 

 of heat from the skin, were shown by experiment to be only secondary 

 causes of the irregular temperature. Observations made upon the effect 

 of affusions of cold water showed that the rectal temperature in infants 

 a day or two old rose in the case of strong subjects, but remained 

 stationary or fell in the case of the weak. Kaudnitz concludes that 

 the imperfect development of the power of regulating temperature is 

 the chief cause of the variable temperature in infants ; and it has been 

 shown by the writer 2 that this is also the cause in the case of young 

 immature animals. 



Before birth the temperature of the infant is slightly higher than 

 that of the mother's uterus ; 3 at birth the average rectal temperature 

 is 37'5 (99'5). Soon after birth, especially after the first bath, the 

 temperature falls to about 36 0- 75 (98*15), and during the next week or 

 two rises somewhat, and remains fairly constant between 37'25 (99'05) 

 and 37'6 (99'68). These figures are to be looked upon only as average 

 results, for all observers appear to agree that the daily fluctuations of 

 temperature are greater and more uncertain in children than in adults. 4 



1 Ztsclir.f. Biol., Miinohen, 1888, Bd. xxiv. S. 423. At tlie end of this paper is a very 

 complete list of papers bearing upon the subject. 



2 Pembrey, Journ. PhysioL, Cambridge and London, 1895, vol. xviii. p. 363. 

 3 Wurster, Berl. klin. Wchnschr., 1869, NT. 37; Alexcetf, Arch. f. GynaeJc., Berlin, 



Bd. x. S. 141; Fehling, ibid., Bd. vii. S. 146; Preyer, " Specielle Physiologic des 

 Embryo/' Leipzig, 1885, S. 362. 



4 Barensprung, Arch. f. Anat., PhysioL u. wissensch. Med., 1851, S. 138; Finlayson, 

 "On the Normal Temperature of Children," Glasgow Med. Journ., 1869, p. 186 ; Squire, 

 Trans. Obst. Soc. London, vol. x. p. 274; Raudnitz, Ztschr. /. Biol., Munchen, 1888, 

 Bd. xxiv. S. 423; here other references will be found; Jiirgensen, "Die Korperwarme 

 des gesunden Menschen," 1873, S. 49 ; Davy, "Researches," London, 1839, vol. i. p. 156 ; 

 Crombie, Indian Ann. Med. Sc., Calcutta, 1873, vol. xvi. p. 594 ; Mignot, These de Paris, 

 1851 ; Wurster, Berl. klin. Wchnschr., 1869, Bd. vi. S. 37 ; Andral, Compt. rend. Acad. 

 d. sc., Paris, 1870, p. 815 ; Roger, Arch. gen. de med., Paris, Ser. 4, tome v. p. 273 ; c | De 

 la temperature chez les enfants," Paris, 1844 ; Lupine, Gaz. med. de Paris, 1870 ; Fehling, 

 Arch.f. GynaeJc., Berlin, 1874, Bd. vi. S. 385. 



