of the work already done, a fair bibliography, and a list of
perforated flowers in Professor L.H. Pammel's paper on the
"Perforation of Flowers," in the _Transactions of the St. Louis
Academy of Science_, vol. v., pp. 246-277.

The general beauty of flowers is usually not greatly marred by the
perforations except in a few cases, as when the spurs of columbines
and corollas of trumpet creepers are much torn, which frequently
happens.

The great object of the perforations by insects is the obtaining of
the concealed nectar in an easy way. Very naturally, flowers which
depend on insect agency for fertilization rarely produce seed when
punctured if they are not also entered in the normal way. Perforating
is only practiced by a small number of species of insects, and many
but not all of the perforators do so because their tongues are too
short to reach the nectar by entering the flower. Some obtain nectar
from the same kind of flower both in the normal way and by
perforating.

The chief perforators of flowers, in this part of the continent at
least, appear to be some kinds of humble bees (Bombus) and carpenter
bees (Xylocopa). These insects have developed an unerring instinct as
to the proper point to perforate the corollas from the outside, in
order to readily get at the nectar. The holes made by the humble bees
and by the carpenter bees are usually quite different and easily
distinguished.

The humble bees have short, stout, blunt jaws, ill adapted for
cutting, and the perforations made by them are apparently always