Hexagonal Cells by Bees and Wasps. 141 
in my opinion, conclusive of the primary intention of the builders 
to erect hexagonal cells. 
L have examined nests of wasps in every stage of progress; I 
have found some species laying a separate foundation for each 
cell, wasps as well as bees; I have found some species of wasps 
constructing the entire foundations of a complete comb before a 
single wall of a cell was erected; and I see bees furnished with a 
complete floor of artificial foundations, at once adopting this ad- 
ventitious aid. ‘Then, again, I observe in nests of Yatua moro, 
and of some other species of wasps, the walls of one, two, three 
or more planes of the hexagon more or less raised ; and, under 
these circumstances, what is the conclusion at which I naturally 
arrive? Why that all hexagonal cells are not constructed upon a 
circular principle, and that the primary idea of all social bees and 
wasps is not to produce cylindrical cells with hemispherical bases. 
1 know not whether any one besides myself has arrived at a 
similar conclusion, or whether I stand alone in the opinion I have 
endeavoured to explain. 
Appenpum.—It having been suggested that the nest of Icaria’ 
gultatipennis, of which I could only exhibit a sketch, might pos- 
sibly be only the portion of a nest ina state of demolition, I have 
re-examined it, and can vouch that such is not the case; only a 
few of the cells being carried up to their full height and lined with 
the exuvie of the larva. It has also been stated that wasps are 
well known to destroy their old nests; such a circumstance is 
quite unknown to me, and I do not remember to have heard such 
a statement previously made. 
In order to place clearly before my readers the fact of Icaria 
building hexagonal cells with exterior portions of the cells angu- 
lated, I have had a drawing of a nest of another species made, in 
which none of the cells are carried up to the required height. 
(See Pl. XIII. fig. A.) All the nests of this genus of wasp ap- 
pear to be constructed in the same manner, the sharpness and 
beauty of the hexagon varying according to the skill of the par- 
ticular species. 
I exhibited a nest of Polistes Tasmaniensis in which a single cell 
was carried up above the surrounding cells, and it has been 
objected to as not being perfectly hexagonal: I have already 
stated that all bees and wasps are not equally skilful workmen, 
those belonging to the genus Polistes being instanced as “ rude 
