TRACHEATA 387 
egos laid by the queen, who can lay at will either fertilised 
or unfertilised ova. 
During the winter the queen-bee and the workers live upon 
the food stored up in the hive; when spring returns she 
deposits eggs, first in the cells of the workers and then of the 
drones. After a time certain large royal cells are constructed, 
and in each of these she lays a fertilised eg¢; the larvae which 
proceed from these eggs receive a richer nourishment and 
become queens. The drones take twenty-four days to de- 
velope, the workers twenty, and the queens sixteen. Before 
the eldest of the royal pupae gives rise to a queen in the 
imaginal state, the queen mother with a number of the workers 
leave the hive and swarm. ‘Thus a new colony arises. The 
young queens fight until all but one are killed, or the others 
swarm ; the victorious one remains as queen of the hive. Soon 
after the metamorphosis is complete the queen is fertilised by a 
drone whilst flying in the air. The drone immediately dies, 
and the queen, which has only been fertilised once, can con- 
tinue to lay fertilised ova for several years. 
A hive may number as many as twenty to thirty thousand 
individuals, of which the drones do not form more than one 
per cent. 
Bombus, the humble-bee, makes underground nests which 
contain from fifty to two hundred individuals. This genus 
does not make cells, but lays its eggs in a mass of pollen 
accumulated in the centre of the nest; the larvae eat their 
way through this, and ultimately turn into pupae. A single 
fertilised female survives the winter, and inaugurates a new 
colony in the following year. 
