402 PHYSIOLOGY. 



temperature in both orders, in illustration of which we refer to the 

 condensed and learned comparisons of G. R. Treviranus *, we will 

 at once proceed to relate the observations that have been made upon the 

 subject of this heat in some insects. 



These insects are the bees and the ants. In the bees Swammerdam 

 was the first to observe a peculiar warmth of the hive in winter, during 

 a very low external temperature f. He supposed this warmth was partly 

 to keep a portion of the honey fluid and partly to assist the eggs in 

 hatching and to prevent the bees from freezing. Since Swammerdam 

 similar observations have been made by MaraldiJ, Reaumur, and Huber. 

 Reaumur observed a thermometer standing at 6| external tem- 

 perature rise in the hive to + 22^; according to Huber the average 

 temperature of the hive in winter is 86 80 F. This warmth 

 increased upon his causing a general motion among the bees by dis- 

 turbing them, and so much so, that the small glass window in the hive 

 soon became hot, whereas, when the bees were quiet and undisturbed, 

 it felt almost cold ; and indeed the wax of the combs melted several 

 times and ran down. From this experiment especially it has been 

 wished to conclude that the warmth in the hive is produced by the 

 motion of the bees, particularly by their occasional general fluttering, 

 which Maraldi considered to be the sole cause of the high temperature 

 of the hive. According to Huber , however, this occasionally repeated 

 fluttering of the bees is produced by them merely to create a current of 

 air, whereby fresh air is introduced^ and that rendered noxious by 

 continued respiration removed. In summer also, and not merely in 

 winter, do they do this, and thereby even at that season produce an 

 equally moderate temperature in the hive, which does not exceed that 

 of the external air. The same has been observed in ant hills, in 

 which the thermometer upon an external temperature of + 10 rose, 

 according to Juch ||, to + 17. In the wasps and humble bees, also, 

 which likewise live in society, we may with great probability infer a 

 similar phenomenon. 



If after such facts it is undeniable that insects under certain circum- 

 stances can produce a higher but equal temperature, nothing further 



* Biologie, t. v. p. 64, &c. Das organisclie Leben, t. i. p. 413, &c. 



\- Biblia Naturae, p. 161. 



J Mein. cle 1' Acad. des Sc. de Paris, 1714, Ed. d' Ainst., p. 420. 



Nouvelles Observ. stir les Abeilles, t. ii. p. 338, &c. 



!| Iileen zu einer Zoochemie, vol. i. p. 9'2. 



