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under these circumstances, the other animal functions are 

 performed with proportionate rapidity. When the insect is 

 at rest the temperature sinks rapidly, which is easily 

 explained hy the enormous proportion of its superficies to 

 its bulk, and the great amount of heat lost hy evaporation. 

 In the Bee, in its greatest state of vital activity, that is, when 

 it is incubating the heat produced, was found by Newport to 

 be twenty times as great as in the state of repose, and the 

 increased production of carbon is in like proportion ; it 

 perspires profusely, and in a very short time gives up the 

 business to another, exhausted, and bathed in sweat. In 

 flying about on a sunny day, the heat produced must be also 

 very great. The temperature, however, of the animal, under 

 these circumstances, would be found, most probably, not to 

 be very high ; because flying through an atmosphere, far 

 from saturated with vapour, the increments of heat 

 arising from its great activity are earned off by the 

 rapid evaporation of the sweat from the larger surfaces 

 of the bee. In the hive, the congregation of a large number 

 of these animals, in a state of activity, must be the source 

 of a great elevation of temperature ; and, were it not for 

 the admirable system of ventilation described by Huber, 

 by which a continued renewal of the air is effected in its 

 most remote recesses, they would not be able to live in the 

 foul and heated air which is the result of this action. At 

 periods of particular excitement, as when they are about 

 to swarm, the temperature of the hive, in spite of 

 ventilation, becomes very high : during their sleep, the 

 temperature falls, and in the profound sleep in which they 

 pass the winter, it is no higher than that of the external 

 atmosphere, being often below that of 32°. If it sink 

 too low, however, the animals are aroused, and, by their 

 exertions, soon warm up the hive. The rapidity with 

 which this elevation of temperature is effected, is shewn by 

 the fact that, hitherto, the best observers have considered 

 the temperature of the hive to differ little in winter 



