And if I had not long been seeking among the Edriophthalma for traces of
the supposititious Zoea-state, and seized with avidity upon everything
that promised to made this refractory Order serviceable to me, Van
Beneden's short statement could hardly have affected me so much in the
manner of an electric shock, and impelled me to a renewed study of the
Tanaides, especially as I had once before plagued myself with them in
the Baltic, without getting any further than my predecessors, and I have
not much taste for going twice over the same ground.


CHAPTER 4. SEXUAL PECULIARITIES AND DIMORPHISM.

Our Tanais, which in nearly all the particulars of its structure is an
extremely remarkable animal, furnished me with a second fact worthy of
notice in connection with the theory of the origin of species by natural
selection.

When hand-like or cheliform structures occur in the Crustacea, these are
usually more strongly developed in the males than in the females, often
becoming enlarged in the former to quite a disproportionate size, as we
have already seen to be the case in Melita. A better known example of
such gigantic chelae is presented by the males of the Calling Crabs
(Gelasimus), which are said in running to carry these claws "elevated,
as if beckoning with them"--a statement which, however, is not true of
all the species, as a small and particularly large-clawed one, which I
have seen running about by thousands in the cassava-fields at the mouth
of the Cambriu, always holds them closely pressed against its body.

A second peculiarity of the male Crustacea consists not unfrequently in
a more abundant development on the flagellum of the anterior antennae of