PERFECT SOCIETIES OF INSECTS. 



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scribed. The time also that they devote to this function is 

 longer or shorter, according to circumstances : some have 

 been observed to continue their vibrations for nearly half an 

 hour without resting, suspending the action for not more 

 than an instant, as it should seem to take breath. When one 

 retires, another occupies its place ; so that in a hive well 

 peopled there is never any interruption of the sound or 

 humming occasioned by this action, by which it may always 

 be known whether it be going on or not. 



This humming is observable not only during the heats of 

 summer, but at all seasons of the year. It sometimes seems 

 even more forcible in the depth of winter than when the tem- 

 perature of the atmosphere is higher. An employment so 

 constant, which always occupies a certain number of bees, 

 must produce as constant an effect. The column of air once 

 disturbed within must give place to that without the hive ; 

 thus a current being established, the ventilation will be per- 

 petual and complete. 



To be convinced that such an effect is produced, approach 

 your hand to a ventilating bee, and you will find that she 

 causes a very perceptible motion in the air. Huber tried an 

 experiment still more satisfactory. On a calm day, at the 

 time when the bees had returned to their habitation — having 

 fixed a screen before the mouth of the hive to prevent his 

 being misled by any sudden motion of the external air — he 

 placed within the screen little anemometers or wind-gauges, 

 made of bits of paper, feather, or cotton, suspended by a 

 thread to a crotch. No sooner did they enter the atmosphere 

 of the bees than they were put in motion, being alternately 

 attracted and repelled to and from the aperture of the hive 

 with considerable rapidity. These attractions and repulsions 

 were proportioned to the number of bees engaged in ven- 

 tilation, and though sometimes less perceptible, were never 

 entirely suspended. Burnens tried a similar experiment in 

 the winter, when the thermometer stood in the shade at 33°. 

 Having selected a well-peopled hive, the inhabitants of which 

 appeared full of life and sufficiently active in the interior, and 

 luted it all around, except the aperture, to the platform on 

 which it stood, he stuck in the top a piece of iron wire which 



