these is the White-faced Decticus (_D. albifrons_, FAB.), the
biggest sabre-bearer of the Provencal fauna. A magnificent insect is
this Grasshopper, with a broad ivory face, a full, creamy-white belly
and long wings flecked with brown. In July, the season for the
wedding-dress, let us dissect him under water.

The adipose tissue, which is abundant and yellowish white, consists of
a lace of wide, irregular, criss-cross meshes. It is a tubular network
swollen with a powdery matter which condenses into minute chalk-white
spots, standing out very plainly against a transparent background.
When crushed in a drop of water, a fragment of this fabric yields a
milky cloud in which the microscope shows an infinite number of opaque
floating atoms, without revealing the smallest blob of oil, the sign
of fatty matter.

Here again we have ammonium urate. Treated with nitric acid, the
adipose tissue of the Decticus produces an effervescence similar to
that of chalk and yields enough murexide to redden a tumblerful of
water. A strange adipose body, this bundle of lace crammed with uric
acid without a trace of fatty matter! What would the Decticus do with
nutritive reserves, seeing that he is near his end, now that the
nuptial season has arrived? Delivered from the necessity of saving for
the future, he has only to spend in gaiety the few days left to him;
he has only to adorn himself for the supreme festival.

He therefore converts into a paint-factory what at first was a
warehouse for storing up foodstuffs; and with his chalk-like uric pulp
he lavishly daubs his belly, which turns a creamy white, and smears it
on his forehead, his face, his cheeks, until they assume the
appearance of old ivory. All those parts, in fact, which lie
immediately under the translucid skin are covered with a layer of
pigment which can be turned into murexide and is identical in nature
with the white powder of the adipose lace.

Biological chemistry can hardly offer a simpler and more striking
experiment than this analysis of the Decticus' finery. To those who
have not this curious Grasshopper handy, I recommend the Ephippiger of
the Vines, who is much more widely distributed. His ventral surface,
which also is of a creamy white, likewise owes its colour to a
plastering of uric acid. In the Grasshopper family many other species
of smaller size and requiring more delicate handling would give us the
same results in varying degrees.

White, slightly tinged