268 s PHYSIOLOGY. 



of their hives, and immediately adopt measures to 

 restore to this element the degree of purity 

 essential to respiration : from some eudiometrical 

 experiments, it has been ascertained that the air 

 of a well stocked hive is as pure as that by which 

 it is surrounded. Still neither wax nor pollen 

 favours the generation of oxygen gas, nor have 

 bees the faculty of generating it ; for when very 

 closely shut up, they perish in a few hours. The 

 writers just referred to, discovered that the bees, 

 by uniting the two wings of each side, by means 

 of the small marginal hooks with which they 

 are provided, so as to make them present the 

 largest possible surface to the air, were capable 

 of striking it with considerable force, and that 

 this force was increased by the wings forming a 

 slight concavity. The wings arranged in this 

 manner, are put into a violent vibratory motion 

 by the bees appointed to the office of ventilators, 

 and produce what we call a draught of air. Fen- 

 tilation is thus systematically accomplished. A 

 certain portion of ventilating bees is stationed in 

 files at the entrance of the hive, with their heads 

 turned inwards ; another and a larger party, in 

 files also, stands a considerable way in the interior, 

 with their heads towards the entrance : thus both 

 these parties cooperate, in producing a current of 

 air in the same direction, and are so arranged as 

 not to interrupt the passage of their fellow-citi- 



