PEKFECT SOCIETIES OF INSECTS. 427 



bees ; but they attributed to it an effect the reverse of that which it really 

 produces ; the former imagining it to occasion directly the high tempera- 

 ture of the hive, and the latter indirectly.^ It was reserved for Huber to 

 discover the true cause of it ; and from him the chief of what I have to 

 say upon the subject will be derived.^ 



During the summer a certain number of workers — for it is to the work- 

 ers solely that this office is committed — may always be observed vibrating 

 their wings before the entrance of their hive ; and the observant apiarist 

 will find, upon examination, that a still- greater number are engaged 

 within it in the same employment. All those thus circumstanced that 

 stand without turn their head to the entrance ; while those that stand 

 within turn their back to it. The station of these ventilators is upon the 

 floor of the hive. They are usually ranged in files that terminate at the 

 entrance ; and sometimes, but not constantly, form so many diverging 

 rays, probably to give room for comers and goers to pass. The number 

 of ventilators in action at the same time varies : it seldom much exceeds 

 twenty, and is often more circumscribed. 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 temperature 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 dis- 

 turbed 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, 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 ventilation, and though sometimes less perceptible, were 

 never entirely suspended. Burnens tried a similar experiment in the win- 

 ter, when the thermometer stood in the shade at 33°. Having selected a 

 well-peopled hive, the inhabitants of which appeared full of life and suf- 

 ficiently active in the interior, jvnd luted it all round, except the aperture, 

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



' Reaum. v. 672. « Huber, ii. 338—362. 



