transparent wings under the _vagina_, or sheath, a huge cap or
helmet on the head, and two _antennae_, or feelers, from beneath
the eyes.

It is chiefly in the advanced period of spring that these insects
commence their noise; and which is the call or signal by which they are
mutually attracted to each other, and may be considered as analogous to
the call of birds. This noise does not arise from their voice, but from
the insect beating on hard substances, with the shield or fore part of
its head. The general number of successive distinct strokes is from 7 to
9 or 11. These are given in pretty quick succession, and are repeated at
uncertain intervals; and in old houses, where the insects are numerous,
they may be heard, if the weather be warm, almost every hour in the day.
The noise exactly resembles that made by beating moderately hard with
the finger on a table. Mr. Stackhouse carefully observed its manner of
beating. He says, the insect raises itself upon its hinder legs, and
with the body somewhat inclined, beats its head with great force and
agility against the place on which it stands.

This insect, which is the _real death-watch_ of the vulgar, must
not be confounded with another minuter insect, which makes a ticking
noise like a watch; but instead of beating at intervals, it continues
its noise for a considerable time without intermission. This latter
belongs to a very different tribe. It is usually found in old wood,
decayed furniture, neglected books, &c.; and both the male and the
female have the power of making this ticking noise, in order to attract
each other. The Rev. Mr. Derham seems to have been the first naturalist
who examined and described this species; and he says that during the
month of July, in one particular summer, they scarcely ever ceased to
beat either in day or night. The eggs are generally hatched about the