THE COMB-BUILDERS 205 
horizontal planes, storey above storey ; but such a 
method of construction would be economically 
unsound, To prevent sagging in the heat of the 
hive, and under the weight they will be called 
to bear, the cell-bases would have to be thickened 
collectively into a substantial floor, which would 
need shoring-up at intervals—after the manner of 
the wasps. But in this, much valuable material 
would be diverted from its proper use. Obviously, 
a better plan would be to lay all the cells on their 
sides, and pile them up into a vertical wall. And, 
just as obviously, if two walls of these super- 
imposed cells were placed back to back, so that 
one central vertical sheet of wax would serve to 
stop the ends of all the cells, right and left, a 
saving of half the material used for the cell-bottoms 
would at once be effected. 
But, so far, the design is still only in its crude, 
initial stage. The upright comb, consisting of a 
double pile of round cells, back to back, with one 
flat base between, although a great advance on the 
single sheet of horizontal cells, is yet mechanically 
and economically deficient. The round cells leave 
useless interstices, which take much wax in the 
filling; while the flat bottoms do not coincide with 
the form of the larvee, and thus still more space is 
wasted, Clearly, improvement can only come by 
altering the shape of the cell; and now the bee 
seems to have asked herself—and triumphantly 
answered—an extremely complex question. 
