Formation of the Cells of Bees and Wasps. 129 
believe I have clearly shown that there is one common principle 
in action exhibited in the work of all these insects—I might 
include the work of other tribes of insects, or I might point to the 
works of other animals, the bird’s nest for instance—and that is 
the principle of working in segments of circles: that the hexa- 
gonal form of the cells of certain bees and wasps may, and 
does, arise out of this mode of action when under certain con- 
ditions: that those conditions are, that the cells are so com- 
menced that their natural circumferences, as the work proceeds, 
are either simply brought into contact with each other, or that the 
cells are so placed that the (we will say theoretical) cireum- 
ferences must intersect. Contact with adjoining cells then is an 
essential condition to bring about the hexagonal form,* but for 
this result it is not necessary that a hexagonal cell should be 
completely surrounded by other cells. 
* As J have before pointed out in this Society’s rooms, See Proc. Ent. Soc. 
1858, p. 17. 
