58 Proceedings of the Royal Society of Victoria. 



themselves and their nests very considerably. As the result of 

 twelve experiments on a nest of thirty bees, Newport found 

 an average elevation of 3-5°; but on seven occasions when he 

 violently agitated them he obtained an average elevation of 5*3°. 

 At times when bees are naturally much excited, as at swarming 

 time, their temperature may rise as much as 22°. According to 

 experiments of Juch and Newport (Phil. Trans., 1837, p. 259), 

 ants in an ordinary state of activity keep their nests some seven 

 or eight degrees warmer than the surrounding air, but when 

 agitated the difference readily rises to twelve or thirteen degrees. 



These more intelligent insects apparently make use of this 

 capacity of generating heat for the purpose of quickening the 

 hatching of eggs and the development of nymphs. Nevertheless 

 they are distinctly cold-blooded animals, for at rest they take the 

 temperature of their media, and any elevation is temporary and 

 due to the immediately preceding display of energy. 



In the case of tish, amphibia and reptiles the same is true. 

 At rest all of them remain at the temperature of their environ- 

 ment, rising and falling with it. and showing no capacity, 

 however rudimentary, of maintaining a fixed and characteristic 

 temperature ; yet all can warm themselves by exertion. The 

 large blue-tongued lizard, which is common in the southern parts 

 of Victoria {Cyclodus gigas), can warm himself as much as half a 

 degree in ten minutes of anger. In five experiments of this sort 

 I found that different individuals had different capacities of being 

 irritated, but the average was a trifle under half a degree for ten 

 minutes of exasperation. 



By activity, and consequent heat-production, all fish, amphibia 

 and reptiles seem able to keep themselves a little warmer than the 

 air or water in which they dwell. Dutroche tells us (Ann. des 

 Sciences Nat., xiii., p. 20) that the newt can keep itself from 2° 

 to 5t?° above the temperature of its medium, the turtle 1^° to 34°, 

 and the common green lizard of France {Lacerta viridis) from 4° 

 to 7°. Max Furbinger asserts that species of blind-worm rise as 

 much as 8° above the temperature of the air. Fish at rest 

 appear to take almost absolutely the temperature of the water 

 wherein they live, but after a struggle, or any other form of 

 energy, they may warm themselves two or three degrees. 



This, however, has no real affinity with a warm-blooded 

 habit. And yet these creatures approach in a remote way the 



