nly pseudochrysalis in my
possession showed me that, similarly to that which happens in the
Sitares, no change occurred in the organization of the viscera,
notwithstanding the profound transformations which take place
externally. In the midst of innumerable little sacs of adipose tissue
is buried a thin thread in which we easily recognize the essential
features of the digestive apparatus, both of the preceding larval form
and of the perfect insect. As for the medullary cord of the abdomen,
it consists, as in the larva, of eight ganglia. In the perfect insect
it comprises only four.

I could not say positively how long the Oil-beetle remains in the
pseudochrysalid form; but, if we consider the very complete analogy
between the evolution of the Oil-beetles and that of the Sitares,
there is reason to believe that a few pseudochrysalids complete their
transformation in the same year, while others, in greater numbers,
remain stationary for a whole year and do not attain the state of the
perfect insect until the following spring. This is also the opinion
expressed by Newport.

Be this as it may, I found at the end of August one of these
pseudochrysalids which had already attained the nymphal stage. It is
with the help of this precious capture that I shall be able to finish
the story of the Oil-beetle's development. The horny integuments of
the pseudochrysalis are split along a fissure which includes the whole
ventral surface and the whole of the head and runs up the back of the
thorax. This cast skin, which is stiff and keeps its shape, is
half-enclosed, as was the pseudochrysalis, in the skin shed by the
secondary larva. Lastly, through the fissure, which divides it almost
in two, a Meloe-nymph half-emerges; so that, to all appearances, the
pseudochrysalis has been followed immediately by the nymph, which does
not happen with the Sitares, which pass from the first of these two
states to the second only by assuming an intermediary form closely
resembling that of the larva which eats the store of honey.

But these appearances are deceptive, for, on removing the nymph from
the split sheath formed by the integuments of the pseudochrysalis, we
find, at the bottom of this sheath, a third cast skin, the last of
those which the creature has so far rejected. This skin is even now
adhering to the nymph by a few tracheal filaments. If we soften it in
water, we easily recognize that it possesses an organization almost
identical with