IB 
IMPREGNATION OF 
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and a glass tube was adapted to the 
entrance, so narrow® that no drone 
could pass, but large enough for the 
free passage of the common bees. In 
the hives of the second class* he left 
all the drones belonging to them, and 
even introduced more ; and to prevent 
their escape, a glass tube was also 
adapted to the entrance of these hives* 
For more than a month he carefully 
watched this experiment made on a 
large scale ; but much to his surprise, 
all the queens remained barren. This 
result induced him to suspect that 
queens could not be fecundated in 
the interior of the hive, and that it 
was necessary for them to leave it 
