04: 
MODE OF RENEWING 
of various durations. We have seen 
them engaged ia it during 25 minutes, 
only taking breath, as it were, by 
the shortest interruption of the vi¬ 
bration. On ceasing, they are suc¬ 
ceeded by other s; so that there is 
never any intermission of bussing in 
a populous hive. 
Retained in their hive by all the 
attractions that nature has there com¬ 
bined for them, and unable to with¬ 
draw from the surrounding mephitic gas 
without abandoning their young toge¬ 
ther with their stores, they have re¬ 
course to ventilation for tho renewal 
of the air. To what can we ascribe 
the general tranquillity, when a few 
