VENTILATION OF THE BEE- HIVE. 177 



is forced out. By a series of beautiful experiments, Huber 

 ascertained that the air of a crowded hive is almost as pure 

 as the surrounding atmosphere. Now, as the entrance to 

 such a hive is often very small, the air within cannot be 

 renewed, without resort to artificial means. If a lamp is 

 put into a close vessel, with only one small orifice, it will 

 soon exhaust the oxygen, and cease to burn. If another 

 small orifice is made, the same result will follow ; but if a 

 current of air is by some device drawn out from one open- 

 ing, an equal current will force its way into the other, and 

 the lamp will burn until the oil is exhausted. 



365. It is on this principle of maintaining a double cur- 

 rent by artificial means, that bees ventilate their crowded 

 habitations. A file of ventilating bees stands inside and 

 outside of the hive, each with head turned to its entrance, 

 and while, by the rapid fanning of their " many twinkling" 

 wings, a brisk current of air is blown out of the hive, an 

 equal current is drawn in. As this important office demands 

 unusual physical exertion, the exhausted laborers are, from 

 time to time, relieved by fresh detachments. If the interior 

 of the hive permits inspection, many ventilators will be 

 found scattered through it, in very hot weather, all busily 

 engaged in their laborious employment. If its entrance is 

 contracted, speedy accessions will be made to their num- 

 bers, both inside and outside of the hive ; and if it is closed 

 entirely, the heat and impurity quickly increasing, the 

 whole colony will attempt to renew the air by rapidly vi- 

 brating their wings, and in a short time, if unrelieved, wiU 

 die of suffocation. 



366. Careful experiments show that pure air is neces- 

 sary not only for the respiration of the mature bees, but for 

 hatching the eggs, and developing the larvae ; a fl.ne netting 

 of air-vessels enveloping the eggs, and the cells of the larvae 

 being closed with a covering flHed with air-holes (168). 



In Winter, if bees are kept in a dark place, which is 

 12 



