wad which, when placed in water, softened and then patiently
unravelled with the tip of a paint-brush, yields a white, powdery
substance, which is uric acid, the usual product of the work of the
nymphosis, and a rumpled membrane, in which I recognize the cast skin
of the nymph. There should still be the tertiary larva, of which I see
not a trace. But, on taking a needle and gradually breaking the
envelope of the pseudochrysalis, after soaking it awhile in water, I
see it dividing into two layers, one an outer layer, brittle, horny in
appearance and currant-red; the other an inner layer, consisting of a
transparent, flexible pellicle. There can be no doubt that this inner
layer represents the tertiary larva, whose skin is left adhering to
the envelope of the pseudochrysalis. It is fairly thick and tough, but
I cannot detach it except in shreds, so closely does it adhere to the
horny, crumbly sheath.

Since I possessed a fair number of pseudochrysalids, I sacrificed a
few in order to ascertain their contents on the approach of the final
transformations. Well, I never found anything that I could detach; I
never succeeded in extracting a larva in its tertiary form, though
this larva is so easily obtained from the amber pouches of the Sitares
and, in the Oil-beetles and Cerocomae, emerges of its own accord from
the split wrapper of the pseudochrysalis. When, for the first time,
the stiff shell encloses a body which does not adhere to the rest,
this body is a nymph and nothing else. The wall surrounding it is a
dull white inside. I attribute this colouring to the cast skin of the
tertiary larva, which was inseparably fixed to the shell of the
pseudochrysalis.

The Zonites, therefore, display a peculiarity which is not offered by
the other Meloidae, namely, a series of tightly-fitting shells, one
within the other. The pseudochrysalis is enclosed in the skin of the
secondary larva, a skin which forms a pouch without an orifice, fitted
very closely to its contents. The slough of the tertiary larva fits
even more closely to the inner surface of the pseudochrysalid sheath.
The nymph alone does not adhere to its envelope. In the Cerocomae and
the Oil-beetles, each form of the hypermetamorphosis becomes detached
from the preceding skin by a complete extraction; the contents are
removed from the ruptured container and have no further connection
with it. In the Sitares, the successive casts are not ruptured and
remain enclosed insid