s it the general appearance that guides her? No, for in some
Bembex-burrows we shall find Sphaerophoriae, those slender, thong-like
creatures, and Bombylii, looking like velvet pincushions; no again,
for in the pits of the Silky Ammophila we shall see, side by side, the
caterpillar of the ordinary shape and the Measuring-worm, a living pair
of compasses which progresses by alternately opening out and closing;
no, once more, for in the storerooms of Stizus ruficornis and the
Mantis-hunting Tachytes we see stacked beside the Mantis the Empusa, her
unrecognizable caricature.

Is it the colouring? Not at all. There is no lack of instances. What
a variety of hues and metallic reflections, distributed in a host of
different fashions, appear in the Buprestes that are hunted by the
Cerceris celebrated by Leon Dufour. (Jean Marie Leon Dufour (1780-1865)
was an army surgeon who served with distinction in several campaigns
and subsequently practised as a doctor in the Landes. He attained great
eminence as a naturalist. Cf. "The Hunting Wasps": chapter 1; also
"The Life of the Spider": chapter 1.--Translator's Note.) A painter's
palette, containing crushed gold, bronze, ruby and amethyst, would find
it difficult to rival these sumptuous colours. Nevertheless the Cerceris
makes no mistake: all this nation of insects, so indifferently attired,
represents to her, as to the entomologist, the nation of the Buprestes.
The inventory of the Hornet's larder will include Diptera clad in grey
or russet frieze; others are girdled with yellow, flecked with white,
adorned with crimson lines; others are steel-blue, ebony black, or
coppery green; and underneath this variety of dissimilar costumes we
find the invariable Fly.

Let us take a concrete example. Ferrero's Cerceris (C. Ferreri, VAN DER
LIND) consumes Weevils. Her burrows are usually lined with Phynotomi
and Sitones both an indeterminate grey, and Otiorhynchi, black or
tan-coloured. Now I have sometimes happened to unearth from her cells
a collection of veritable jewels which, thanks to their bright metallic
lustre, made a most striking contrast with the sombre Otiorhynchus.
These were the Rhynchites (R. betuleti), who roll the vine-leaves into
cigars. Equally magnificent, some of them were azure blue, others copper
gilt, for the cigar-roller has a twofold colouring. How did the Cerceris
manage to recognize in these jewels the Weevil, the near relative of
the vulgar Phynotomus? Any such