of the cuticle. This
shortening of the legs is still more marked in the larvae of the
Longhorn Beetles (Cerambycidae) burrowing in the wood of trees or felled
trunks; here the legs are reduced to small vestiges.

[Illustration: Fig. 16. _a_, Grain Weevil (_Calandra granaria_); _b_,
larva; _c_, pupa. Magnified 7 times. After Chittenden, _Yearbook U.S.
Dept. Agric._ 1894.]

Finally in the large family of the Weevils (Curculionidae, fig. 16) and
the Bark-beetles (Scolytidae), the grubs, eating underground root or
stem structures, mining in leaves or seeds, or tunnelling beneath the
bark of trees, have no legs at all, the place of these limbs being
indicated only by tiny tubercles on the thoracic segments. Such larvae
as these latter are examples of the type called _eruciform_ by A.S.
Packard (1898) who as well as other writers has laid stress on the
series of transitional steps from the campodeiform to the eruciform type
afforded by the larvae of the Coleoptera.

A fact of much importance in the transformations of beetles as pointed
out by Brauer (1869) is that in a few families, the first larval instar
is campodeiform, while the subsequent instars are eruciform. We may take
as an example of such 'hypermetamorphosis' the life-story of the Oil or
Blister-beetles (Meloidae) as first described by J.H. Fabre (1857), and
later with more elaboration by H. Beauregard (1890). From the egg of one
of these beetles is hatched a minute armoured larva, with long feelers,
legs, and cerci, whose task is, for example, to seize hold of a bee in
order that the latter may carry it, an uninvited guest, to her nest.
Safely within the nest, the little 'triungulin' beetle-grub moults; the
second instar has a soft cuticle and relatively shorter legs, which, as
the larva, now living as a cuckoo-parasite, proceeds to gorge itself
with honey, soon appear still further abbreviated. Later comes a stage
during which legs are entirely wanting, the larva then resting and
taking no food. The last larval instar again has short legs like the
grub of the second period. In connection with this life-history we
notice that the newly-hatched larva is not in the neighbourhood of its
appropriate food. Hence the preliminary armoured and active instar is
necessary in order to reach the feeding place; this journey
accomplished, the eruciform condition is at once assumed.

In all cases indeed we may say that the particular larval form is
adapted to the special co