The Descent of Man

species of Bledius (Fig. 23), also belonging to
the Staphylinidae, Professor Westwood states
that, "male specimens can be found in the same
locality in which the central horn of the thorax
is very large, but the horns of the head quite
rudimental; and others, in which the thoracic
horn is much shorter, whilst the protuberances
on the head are long." (67. 'Modern Classification
of Insects,' vol. i. p. 172: Siagonium, p. 172.
In the British Museum I noticed one male specimen
of Siagonium in an intermediate condition,
so that the dimorphism is not strict.) Here
we apparently have a case of compensation,
which throws light on that just given, of the
supposed loss of the upper horns by the males
of Onitis.
LAW OF BATTLE.
Some male beetles, which seem ill-fitted for
fighting, nevertheless engage in conflicts for the
possession of the females. Mr. Wallace (68. 'The