The Descent of Man

of this book appeared, besides that already given
of the stickleback. Mr. W.S. Kent says that
the male of the Labrus mixtus, which, as we
have seen, differs in colour from the female,
makes "a deep hollow in the sand of the tank,
and then endeavours in the most persuasive
manner to induce a female of the same species
to share it with him, swimming backwards and
forwards between her and the completed nest,
and plainly exhibiting the greatest anxiety for
her to follow." The males of Cantharus lineatus
become, during the breeding-season, of deep
leaden- black; they then retire from the shoal,
and excavate a hollow as a nest. "Each male
now mounts vigilant guard over his respective
hollow, and vigorously attacks and drives
away any other fish of the same sex. Towards
his companions of the opposite sex his conduct
is far different; many of the latter are now distended
with spawn, and these he endeavours
by all the means in his power to lure singly to
his prepared hollow, and there to deposit the