196 PERFECT SOCIETIES OF INSECTS. 



winter than when the temperature of the atmosphere 

 is higher. An emplpyment 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 

 perpetual and complete. 



To be convinced that such an effect is produced, ap- 

 proach 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 satisfac- 

 tory. On a calm day, at the time when the bees had 

 returned to their habitation — having fixed a screen be- 

 fore the mouth of the hivi 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 ventilation, and, though 

 sometimes less perceptible, were never entirely sus- 

 pended. 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 terminated in a hook, to which 

 he fastened a hair with a small square of very thin pa- 



