outward form of any larva and its mode of life.  For example, in the family of the Leaf-beetles (Chrysomelidae) some larvae feed openly on the foliage of trees or herbs, while others burrow into the plant tissues.  The exposed larvae of the Willow-beetles (Phyllodecta, fig. 14) have their somewhat abbreviated body segments protected by numerous spine-bearing, firm tubercles.  But the grub of the ‘Turnip Fly’ (Phyllotreta) which feeds between the upper and lower skins of a leaf, or of Psylliodes chrysocephala (fig. 15), which burrows in stalks, has a pale, soft cuticle like that of a caterpillar.

[Illustration:  Fig. 14. (a) Willow-beetle (Phyllodecta vulgatissima) and its larva (b).  Magnified 5 times.  After Carpenter, Econ.  Proc.  R. Dublin Soc. vol.  I.]

[Illustration:  Fig. 15. (a) Cabbage-beetle (Psylliodes chrysocephala) magnified 5 times, and its larva (b) magnified 12 times.]

In the larvae of the little timber-beetles and their allies (Ptinidae), including the ‘death-watches’ whose tapping in old furniture is often heard, a marked shortening of the legs and reduction in the size of the head accompany the whitening and softening 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;