characterises families in which the imago shows the greatest
specialisation, while in the same life-story, as in the case of the
oil-beetles (pp. 56-7), the newly-hatched grub may be campodeiform,
changing to the eruciform type as soon as it finds itself within reach
of its host's rich store of food.

A certain amount of difficulty may be felt with regard to the theory of
divergent evolution between imago and larva, in the case of those
insects with complete transformation whose grubs and adults live in much
the same conditions. By turning over stones the naturalist may find
ground-beetles in company with the larvae of their own species. On the
leaves of a willow tree he may observe leaf-beetles (Phyllodecta and
Galerucella) together with their grubs, all greedily eating the foliage;
or lady-bird beetles (Coccinella) and their larvae hunting and devouring
the 'greenfly.' All of these insects are, however, Coleoptera, and the
adult insects of this order are much more disposed to walk and crawl and
less disposed to fly than other endopterygote insects. Their heavily
armoured bodies and their firm shield-like forewings render them less
aerial than other insects; in many genera the power of flight has been
altogether lost. It is not surprising, therefore, that many beetles,
even when adult, should live as their larvae do; since the acquirement
of complete metamorphosis they have become modified towards the larval
condition, and an extreme case of such modification is afforded by the
wingless grub-like female Glow-worm (Lampyris).

With most insects, however, the larva must be regarded as the more
specially modified, even if degraded, stage. Miall (1895) has pointed
out that the insect grub is not a precociously hatched embryo, like the
larvae of multitudes of marine animals, but that it exhibits in a
modified form the essential characters of the adult. Comparison for