Hexagonal Cells by Bees and Wasps. 139 
effected. The cells beyond the intermediate elongated ones will 
be found to be regular hexagons of the increased dimensions re- 
quired. When I see such a departure from the usual mode of 
building as this, I recognize an intelligence that forces me to ac- 
knowledge in the wasp a creature that evidently designs an end to 
be accomplished, not a creature that would instinctively construct 
cylindrical cells, but whose labours always eventuate in the pro- 
duction of hexagonal ones, this result being dependent upon un- 
controllable circumstances which always present themselves. 
(See Pl. XIII. fig. C.) 
Five years ago, when the circular theory was brought before 
this Society, it did not appear in the same guise as now; it was 
then surrounded by certain collateral conditions, which I was led 
to believe were corner-stones of the ingenious edifice. Combina- 
tion of labour was deemed essential, and at one period it was 
supposed that no solitary bee or wasp could construct hexagonal 
cells ; this latter supposition proved to be a fallacy when I in- 
stanced the queen wasp as a solitary builder. In 1862, the Rev. 
Samuel Haughton, in a paper read before the Natural History 
Society of Dublin, says the hexagonal form of cell ‘ may be ac- 
counted for simply by the mechanical pressure of the insects 
against each other during the formation of the cell. In conse- 
quence of the instinct that compels them to work with reference 
to a plane, and of the cylindrical form of the insects’ bodies, 
the cells must be hexagons.” This theory is, I think, at once 
disproved by the instance of the solitary wasp. 
Another condition, essential (as I understood it) to the stability 
of the circular theory, was that no cell could possibly be con- 
structed of the hexagonal form into which the builder could not 
insert its head. I exhibit the foundation comb of a wasp, and 
also the insect that constructed it (No. 6 in the box of specimens); 
I have taken off the head of the wasp and placed it over one of 
the cells, in order to show the impossibility of its being inserted. 
The next condition that formerly existed was a circumstance 
that was supposed to regulate or determine the width of the 
planes of the hexagon ; the explanation was this—a working bee 
was supposed to place itself exactly opposite the centre of one of 
the planes, and then fixing itself steadily in the proper position, 
the width of the plane would be the exact distance that the bee 
cut or reached with its mandibles when turning its head as upon 
a pivot. Now this at first sight appears a very ingenious solution ; 
apparently it accounts admirably for the uniform exactitude ob- 
servable in the width of all the planes; the uniformity of size in 
