196 PEIIFKCT SOCIETIES OF INSECTS. 



tinues in the part wliich feels the heat of the sun. The 

 same cause produces a similar effect upon humble-bees, 

 wasps, and hornets. 



Amongst the bees, however, it is remarkable that ven- 

 tilation goes on even in the depth of winter, when it can- 

 not be occasioned by excess of heat. — This therefore can 

 only be regarded as a secondary cause of the phenome- 

 non. From other experiments, which, having already 

 detained you too long, I shall not here detail, it appears 

 that penetrating and disagreeable odours produce the 

 same effect '. Perhaps, though Huber does not say this, 

 the odour produced by the congregated mj-riads of the 

 hive may be amongst the principal motives that impel 

 its inhabitants to this necessary action. 



Whatever be the proximate cause, it is I trust now 

 evident to you, that the Author of nature, having as- 

 simied to these insects a habitation into which the air 

 cannot easily penetrate, has gifted them with the means 

 of preventing the fatal effects which would result from 

 corrupted air. An indirect effect of ventilation is the ele- 

 vated temperature which these animals maintain, without 

 any effort, in their hive :— but upon this I shall enlarge 

 hereafter. 



Bees are extremely neat in their persons and habita- 

 tions, and remove all nuisances with great assiduity, at 

 least as far as their powers enable them. Sometimes 

 slugs or snails will creep into a hive, which with all 

 their address they cannot readily expel or carry out. 

 But here their instinct is at no loss ; for they kill them, 

 and afterwards embalm them with propolis, so as to pre- 

 vent any offensive odours from incommoding them. An 

 * Iluber, ii. .'i5!) — 



