The Descent of Man

some degree probable in those groups which
possess other well- marked secondary sexual
characters. Blind beetles, which cannot of course
behold each other's beauty, never, as I hear
from Mr. Waterhouse, jun., exhibit bright colours,
though they often have polished coats;
but the explanation of their obscurity may be
that they generally inhabit caves and other obscure
stations.
Some Longicorns, especially certain Prionidae,
offer an exception to the rule that the sexes of
beetles do not differ in colour. Most of these
insects are large and splendidly coloured. The
males in the genus Pyrodes (63. Pyrodes pulcherrimus,
in which the sexes differ conspicuously,
has been described by Mr. Bates in
'Transact. Ent. Soc.' 1869, p. 50. I will specify the
few other cases in which I have heard of a difference
in colour between the sexes of beetles.
Kirby and Spence ('Introduct. to Entomology,'
vol. iii. p. 301) mention a Cantharis, Meloe,