28 THE ESSEX NATURALIST.
In the spring of 1923 I provided a number of nesting tubes,
and my rose trees soon gave abundant evidence of the bees' appre-
ciation : the many pleasant hours I spent watching them at their
work amply repaid me for all damage. My invitation extended
to all tube-using bees, not leaf-cutters only, but, owing to the
cold and damp weather of the early summer, bees were very
scarce and I had no other tenants. The usual number of cells
in a tube was eight, one bee filled two tubes, making 15 cells,
while another used three, eight cells in each of the first two and
four only in the last. The cells, which are
about 5/8" in length, are composed entirely of
portions of green leaves, with the exception of
small fragments of wood, to which I shall allude
later.
In constructing the first cell work was, in
every case observed, commenced on the walls :
elongated pieces of leaf were used ; if, as some-
times happened, a piece was obstructed in any
way, the bee seldom tried to replace it, but
pressed it firmly to the side of the tube, cutting
off any projecting parts and using them as
patches. On completion of the first cell the
much slower work of storing it with food for
the coming grub commenced : this food consists
of pollen mixed with nectar. When the bee
returned with its load of pollen it always entered
the cell head-first, and thoroughly brushed its
head and the forepart of its body, to which a
quantity of pollen adhered, and, I believe, though
the cell walls prevented me from seeing, that it

Fig. 2.
was at this time the nectar was mixed with the
pollen. It then turned round, a somewhat difficult task in the
narrow tube, and unloaded the pollen from the underside of the ab-
domen, where the special arrangement of hairs acts as a receiving
basket. That it is not confined to one particular kind of flower is
shown by the pollen sometimes being of a grey and at other times
of a bright golden colour, or, of various shades between the two.
While the bee is cleaning its abdomen it executes a slow revolving
movement, accompanied by a rising and falling of the body. The
construction of the divisions between the cells calls for much
strenuous labour, and takes some considerable time ; circular