NATURAL HISTORY OF THE HONEY-BEE. 
45 
cell is made not of pure wax, but of a mixture of bee- 
bread and wax ; and appears under the microscope to be 
full of tine holes, to give air to the inclosed insect. From 
its texture and shape it is easily thrust off by the bee 
when mature, whereas if it consisted wholly of wax, the 
insect would either perish for lack of air, or be unable to 
force its way into the world. Both the material and shape 
of the lids which close the honey-cells are different: they 
are of pure wax, and thus air-tight, to prevent the honey 
from souring or candying in the cells ; and are slightly 
concave, the better to resist the pressure of their contents. 
To return to Bevan. “ The larva is no sooner perfectly 
inclosed than it begins to line the cell by spinning round 
itself, after the manner of the silk-worm (PI. XIII., Fig. 
4a), a whitish silky film, or cocoon, by which it is encased, 
as it were, in a pod. When it has undergone this change, 
is has usually borne the name of nymph, or pupa. It has 
now attained its full growth, and the large amount of 
nutriment which it has taken serves as a store for devel- 
oping the perfect insect. 
“The working bee-nymph spins its cocoon in thirty-six 
hours. After passing about three days in this state of 
preparation for a new existence, it gradually undergoes so 
great a change (PI. XIII., Fig. 43) as not to wear a ves- 
tige of its previous form. 
“ When it has reached the twenty-first day of its exist- 
ence, counting from the time the egg is laid, it comes 
forth a perfect winged insect. The cocoon is left behind, 
and forms a closely attached and exact lining to the cell 
in which it was spun ; by this means the breeding cells 
become smaller, and their partitions stronger, the offener 
they change their tenants ; and may become so much 
diminished in size, as not to admit of the perfect develop- 
ment of full-sized bees. 
