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-ordinations of structure; to deny this seems to do no less than to affirm a startling paradox.
Mr.Darwin explains the appearance of some structures, the utility of which is not apparent, by the existence of certain "laws of correlation." By these he means that certain parts or organs of the body are so related to other organs or parts, that when the first are modified by the action of "Natural Selection," or what not, the second are simultaneously affected, and increase proportionally or possibly so decrease.

Examples of such are the hair and teeth in the naked Turkish dog, the general deafness of white cats with blue eyes, the relation between the presence of more or less down on young birds when first hatched, and the future colour of their plumage,[36] with many others.

But the idea that the modification of any internal or external part of the body of an Echinus carries with it the effect of producing elongated, flexible, triradiate, snapping processes, is, to say the very least, fully as obscure and mysterious as what is here contended for, viz.