There is a kind of humble-bee that builds a cone-shaped nest of
clay against a stone or in some similar situation, besmearing the clay
with something like spittle. And this nest or hive is exceedingly
thick and hard; in point of fact, one can hardly break it open with
a spike. Here the insects lay their eggs, and white grubs are produced
wrapped in a black membrane. Apart from the membrane there is found
some wax in the honeycomb; and this a wax is much sallower in hue than
the wax in the honeycomb of the bee.