392 SCIENCE PROGRESS. 



acute rheumatism and scarlet fever, to such an extent that 

 death would appear to ensue directly from the great rise 

 of temperature causing coagulation of some of the proteids 

 of the tissues. Still again, in the case of certain hibernat- 

 ing mammals, we know that the nervous system, though 

 still in perfect working order, permits the temperature of 

 the body to fall as low as 2°, and to be but a fraction of 

 a degree above that of the surroundings. Yet in these 

 cases the heat regulating mechanism is only temporarily in 

 abeyance. If irritated, and caused to awake from their 

 torpor, these animals are able in a very short space of time 

 to raise their body temperatures through a considerable 

 temperature interval. Thus Pembrey and Hale White : 

 record a case in which a dormouse was observed to raise 

 its temperature from 13'$° to 3575° in an hour's time. The 

 existence of these hibernating animals proves that there 

 is no absolute barrier between the warm- and cold-blooded 

 animals. Non-hibernating warm-blooded animals may, in- 

 deed, for the time being, be practically converted into cold- 

 blooded ones by the administration of curare, or by section 

 of the spinal cord in the cervical region. In animals so 

 treated, the carbonic acid output and body temperature 

 rapidly fall, and only rise again on exposure to artificial 

 warmth. 



Just as there has been a physiological evolution in the 

 direction of increased body temperature as we pass from 

 the lower orders of mammals to the higher, so we find a 

 somewhat similar condition of affairs amongst the various 

 orders of birds. Thus of the Ratitse, the lowest of the 

 orders, the cloacal temperature of the ostrich was found by 

 Hobday, 2 as a mean of observations on five different 

 specimens, to be only 2>7'3°, whilst the temperature of 

 the emu was found by Le Souef 8 to be 39"5°. Of the 

 orders of Anseres, Columbse and Galli the following data 

 have been obtained. 4 



1 J. Physiol., vol. xix., p. 477. 



2 Journ. Comp. Path, and Therap., vol. ix., p. 286, 1896. 



3 Vide Sutherland's paper, ibid. 



4 Vide Schafer's Text-book of Physiology, vol. i., p. 791. 



