THE SONG OF THE HIVES 105 
principles, impelled by their especial needs. The 
economy of the hive requires the temperature to be 
absolutely and immediately within the control of the 
bees, and this is only possible when the ventilatory 
system is entirely mechanical. The evaporation of 
moisture from the new-gathered nectar, and the 
hatching of the young brood, necessitate an amount 
of heat much less than that required for wax- 
generating; as soon as the wax-makers begin to 
cluster the temperature of the hive is at once 
increased. But if a current of air were continually 
passing through the hive these necessary heat 
variations would be difficult to manage, even 
supposing them possible at all; so the bees have 
invented their unique system of a single passage- 
way, combined with an ingenious and complicated 
process of fanning, by which the fresh air is sucked 
in at one side of the entrance and the foul air drawn 
out at the other, the atmosphere of the hive being 
thus maintained in a constant state of circulation, 
fast or slow, according to the temperature needed. 
In the hot summer weather these fanning-parties 
are at work continuously, being relieved by others 
at intervals of a few minutes throughout the day. 
But at night, when the whole population of the hive 
is at home, the need for ventilation is greatly 
augmented, and then the open lines of fanners often 
stretch out over the alighting-board six or seven 
ranks deep, making an harmonious uproar that, on 
a still night, will travel incredible distances. 
This tense, forceful labour-song of the bee-garden, 
heard unremittingly throughout the hours of dark- 
ness, is always pleasant, often indescribably soothing 
in its effect. But it is essentially a communal note, 
