PERFECT SOCIETIES OP INSECTS. 211 



and 88 in populous hives a . In May, the former au- 

 thor found, in a hive in which he had lodged a small 

 swarm, that the thermometer indicated a degree of heat 

 above that of the hottest days of summer 5 . He ob- 

 serves that their motion, and even the agitation of their 

 wings, increases the heat of their atmosphere. Often, 

 when the squares of glass in a hive appeared cold to the 

 touch, if either by design or chance he happened to 

 disturb the bees, and the agglomerated mass in a tumult 

 began to move different ways, sending forth a great 

 hum, in a very short time so considerable an accession 

 of heat was produced, that when he touched the same 

 squares of glass, he felt them as hot as if they had been 

 held near a fierce fire. By teasing the bees, the heat 

 generated was sometimes so great as to soften very much 

 the wax of the combs, and even to cause them to fall c . 

 This generation of heat in bee-hives seems to be one of 

 those mysteries of nature that has not yet been satisfac- 

 torily accounted for. Generally speaking, insects ap- 

 pear to have no animal heat ; the temperature of their 

 bodies being usually that of the atmosphere in which 

 they happen to be. But bees are an exception to this 

 rule, and produce heat in themselves. Whether they 

 are the only insect that can do this, as John Hunter af- 

 firms, or whether others that are gregarious, such as 

 humble-bees, wasps, and ants, may not possess the same 

 faculty, seems not yet clearly ascertained. The heat in 

 the hive in the above instance was evidently occasioned 

 by the tumult into which the bees were put ; and the 

 hum, and motions that followed it, were probably the 

 result of their anger. But how these act physically, 

 a i. 354. Note *. b ubi supr. c Reaura. v. 672. 



