mother, it must be starved? The struggle by the sole
action of which such a form was developed must indeed have been severe!

[Illustration: AN ECHINUS, OR SEA-URCHIN
(The spines removed from one-half.)]

The sea-urchins (Echinus) present us also with structures the origin of
which it seems impossible to explain by the action of "Natural {44}
Selection" only. These lowly animals belong to that group of the star-fish
class (Echinodermata), the species of which possess generally spheroidal
bodies, built up of multitudinous calcareous plates, and constitute the
order Echinoidea. They are also popularly known as sea-eggs. Utterly devoid
of limbs, the locomotion of these creatures is effected by means of rows of
small tubular suckers (which protrude through pores in the calcareous
plates) and by moveable spines scattered over the body.

[Illustration: PEDICELLARIAE. (Immensely enlarged.)]

Besides these spines and suckers there are certain very peculiar
structures, termed "Pedicellariae." Each of these consists of a long slender
stalk, ending in three short limbs--or rather jaws--the whole supported by
a delicate internal skeleton. The three limbs (or jaws), which start from a
common point at the end of the stalk, are in the constant habit of opening
and closing together again with a snapping action, while the stalk itself
sways about. The utility of these appendages is, even now, problematical.
It may be that they remove from the surface of the animal's body foreign
substances which would be prejudicial to it, and which it cannot otherwise
get rid of. But granting this, what would be the utility of the _first
rudimentary beginnings_ of such structures, and how could such incipient
buddings have ever preserved the life of a single Echinus? It is true that
on Darwinian principles the ancestral form from which the sea-urchin
developed was different, and must not be conceived merely as an Echinus
devoid of pedicellariae; but this makes the difficulty none the less. It is
equally hard to imagine that the first rudiments of such structures could
have been useful to _any_ animal from which the Echinus might have been{45}
derived. Moreover, not even the _sudden_ development of the snapping action
could have been beneficial without the freely moveable stalk, nor could the
latter have been efficient without the snapping jaws, yet no minute merely
indefinite variations could simultaneously evolve these complex
co-ordination