I'KnFF.CT SOCrKTIES OF INSECTS. 193 



heats of summer, but at all seasons of the year. It some- 

 times seems even more forcible in the depth of winter 

 than when the temperature of the atmosphere is higher. 

 An employment so constant, which always occupies a 

 certain number of bees, must produce as constant an ef- 

 fect. The column of air once disturbed within, must 

 give place to that without the hive ; thus a current be- 

 ing 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 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 pa- 

 per, feather, or cotton, susjiended 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 rapidit}-. These attractions and repulsions 

 were proportioned to the number of bees engaged in 

 ventilation, and, though sometimes less perceptible, were 

 never intirely suspended. Burnens tried a similar ex- 

 periment 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 suffi- 

 ciently active in the interior, and luted it all around, ex- 

 cept the aperture to the platform on which it stood, he 

 stuck in the top a piece of iron wire which terminated in 



VOL. ri. o 



