200 THE FAIRY-LAND OF SCIENCE. 
the ends of three cells meeting it from the opposite 
side (A, Fig. 56), while they fit into the spaces around 
it. Upon this plan the clever little bees fill every 
atom of space, use the least possible quantity of wax, 
Fig. 56. 
B shows in the centre the closed end of a cell which would fit into 
the space in the centre of the three closed cells in A, while the ends of 
these three would fit into the spaces in B. c, d t side-view of cells. 
and make the cells lie so closely together that the 
whole comb is kept warm when the young bees are 
in it. 
There are some kinds of bees who do not live in 
hives, but each one builds a home of its own. These 
bees such as the upholsterer bee, which digs a hole in 
the earth and lines it with flowers and leaves, and the 
mason bee, which builds in walls do not make six- 
sided cells, but round ones, for room is no object to 
them. But nature has gradually taught the little hive- 
bee to build its cells more and more closely, till they 
fit perfectly within each other. If you make a number 
of round holes close together in a soft substance, and 
then squeeze the substance evenly from all sides, the 
rounds will gradually take a six-sided form, showing 
that this is the closest shape into which they can be 
compressed. Although the bee does not know this, 
