218 THE ESSEX NATURALIST.
up to prevent its escape. On opening the hole after a few
days I found that the larva was resting quietly on the floor of
a spherical cell with smooth firm walls, its head and tail slightly
curved over its back. It lay thus for some days, but never
turned on to its back even when disturbed.
Various authorities were referred to for guidance. Fowler5
says "the larva when full grown quits the water and forms
"an oval cell in the adjacent bank."
Miall, in his account of this beetle, refers to Lyonnet's
description,6 published in 1829 long after his death. He prefaces
his remarks by some details of the life and work of Lyonnet
and gives quotations referring to various incidents in the life
history of the insect. References to the full fed larva are
abstracted from Miall's translation.
"A larva 3 inches long," says Lyonnet, "was discovered
"in the middle of August on the grass at the foot of a tree.
. . . I put it upon freshly turned up soil on which I
"scattered some grass. It made a hole which it lined with the
"grass and remained within it several days in a curved position
"lying on its back." (The italics are mine.)
The larva pupated later on, but owing to a wound it died
without further change of form.
Lyonnet reared a number of larvae in order to observe the
process of pupation and the form of the pupa, but met un-
expected difficulties. One larva came out of the water and ran
around his room. It was put back and another came out and
was put in a dish containing earth and grass. It died in two
days, and several others suffered the same fate.
Finally one made a cell with an opening on one side. The
pupa was observed later, but was unable to free itself from the
larval skin. Lyonnet endeavoured, but unsuccessfully, to assist
it and came to the conclusion that the earth supplied was not
sufficiently damp. He therefore took a larva which had been
wandering for fifteen days here and there on the earth without
trying to enter it. He placed it in a large leaden box filled
with earth much damper than before. "The larva then entered
"the earth and changed some days later to a well formed white
"pupa bearing three brown hooks on each side of its head and
5 Coleop. Brit. Isles, I., 220.
6 Memoires du Museum, xviii., 438-457.