384 SCIENCE PROGRESS. 



bird, which has a body temperature of over 40°, is only some 

 ten to twenty times greater than that of a frog, of equal 

 weight, at a temperature of 30°, though it is some fifty to a 

 hundred times as great as that of a frog at 15 . With a 

 more efficient protection against heat loss, it therefore fol- 

 lows that the temperature of cold-blooded animals would be 

 several degrees above that of their surroundings. Thus it 

 would need a proportionately much smaller degree of heat- 

 production to keep an animal 5 above the environmental 

 temperature than to keep it 25 . In a few cases it has been 

 shown that in cold-blooded animals the body temperature 

 may be raised considerably above the external temperature. 

 Thus Davy 1 found the temperature of the shark to be 1 '3°, 

 and of the bonito ( Thynnus pelamys) to be no less than 

 io° above that of the water in which they were kept. 

 Again, the temperature of reptiles may be raised still more 

 •considerably. John Hunter 2 found the temperature of a 

 viper to be raised 5*6°, and Sclater 3 found the temperature 

 of a male python on two occasions to be respectively 9*0° and 

 8*8°, and that of an incubating female no less than 127 and 

 20'o° above that of the air. Forbes made similar observa- 

 tions, 4 and found the temperature of a male python to be 

 6 '4°, and of a female 9*3°, above the air temperature. 

 Still again, Dutroche 5 finds that the temperature of the 

 green lizard (Lacerta viridis) may be from 4 to 7 above 

 that of the atmosphere. The high temperature which 

 beehives may attain is well known. Thus Newport 1 ' found 

 that on one occasion, when the temperature of the air was 

 -7 *5°, that of a hive was — i*i°. When the bees were dis- 

 turbed by tapping the hive, the temperature was raised to 

 21*1° in fifteen minutes. On another occasion, when the 

 external temperature was 1 '4°, that of the hive full of active 

 bees was 3 8 "9°. It is obvious, however, that the bees can 



1 Researches, vol. i., p. 189, 1839. 



•2 Works, Palmer's edition, vol. iv., p. 131, 1837. 



3 Proc. Zool. Soc, 1862, p. 365. 



4 Proc. Zool. Soc, 1 88 1, p. 960. 



5 Ann. des Sciences Nat., xiii., p. 20. 



6 Phil. Trans., 1837, pt. ii., p. 253. 



