supreme God, is a piece of elementary philosophy and religion, which, I conceive, Sir, none of your correspondents can have any wish to dispute; but that the writer of Genesis anticipated by his scientific knowledge the epoch of Copernicus and Newton, Young and Fresnel, Linnæus, De Jussieu and Cuvier, is not only not proven by the few simple phrases of his writings that have anything remotely to do with the branches of science which they so nobly illustrated; much more than this, it would be a disgrace and heavy imputation upon him had he known all they believed, and yet expressed himself so badly as to leave the world for thousands of years in ignorance of the very germs of the true theories, so obscurely that no one should ever have dreamed that he was alluding to the true theories till after they had been independently discovered.

Your correspondent 'X' will find both his pleasure and his profit in reading the chapter on Instinct in 'Darwin's Origin of Species.' It will give him some idea, I say not, how the reasoning faculty was first acquired, but how it may have been gradually developed. By a careful study of the same work he, and many others who need the knowledge, will see that in accordance with Darwinism the deterioration of a species is quite possible. His quaintly expressed argument about Adam's 'immediate progenitor' omits to notice that in the moral world it is a step upward to become capable of sinning, just as in the physical world it is a step upward to become capable of dying, so that the wretchedest man with reason is higher in the scale than the noblest

dog, and the humblest plant than the costliest and most beautiful stone. The other difficulty which he puts forward of an abrupt transition between the first man with reason and the parents of such a man without reason is a difficulty, like that in regard to the first vertebrate, one of words rather than of facts. As with the origin of language and of languages, as with the origin of the natural kingdoms and of every individual form of life, so with the origin of reason; could we see the whole series of steps, with their infinitely numerous and sometimes almost infinitely fine and subtle points of discrimination, we should probably be unable to fix upon any one definite division and say, here noise ends and articulate language begins; or, here Saxon ends and English begins; or, this is the top of instinct, and this the dawn of reason.

OYSTERS OF THE CHALK,

AND THE THEORY OF DEVELOPMENT 1.

THE interesting notice in your last number, of M. Coquand's Oysters of the Chalk,' draws inferences unfavourable to the theory of development or evolution which scarcely seem warranted by the facts. It need not be difficult to imagine the creature as existing under such conditions, that one species, while engaged in "the struggle for existence," should starve out and extinguish another;' for however widely we may find a fossil species dispersed, it is not probable that it occupied the whole of its territory at one and the same time, and in the limited area occupied immediately before its extinction, new varieties may have prevailed over and displaced the old by some slightly superior adaptation to the food-supply of the region. The extinction of any particular species may in some instances have been due to the extinction, or loss by other means, of its own appropriate food. Again, it is not necessary to suppose that the hinge, or the internal or external structure of the shell of an oyster, has been altered by

1 Reprinted from 'Nature,' No. 30.

what may be called the direct action of 'natural selection,' since by the well-established principle of 'correlation' the variation in one part of an organism is nearly or quite certain to produce variations in other parts. If any such change did occur,' it is argued, 'it must have been per saltum, since with these mollusks, numerous as they are, there are no forms that can fairly be recognised as transitional.' But this appeal to the evidence of facts is somewhat premature. The immense difference pointed out between the geological records of England and France in regard to these very oysters of the chalk, leaves it perfectly open for us to suppose that even the comparatively full French record is itself exceedingly imperfect, and that the transitional forms have either not been preserved, or remain yet to be discovered. Mr. Darwin gives reasons for believing that when variation once begins it continues with some vigour; hence, between two settled wide-spread species connected genealogically together we might expect a large number of transitional varieties, each represented by only a few individuals, so that the whole number of these transitional forms might well be lost to the genealogical record.

Finally, the objection from the scarcity of oysters at the present day, compared with the great abundance of species in the past, does not really touch the theory of development, which is concerned to explain how species come into existence, not how they go out of it. That varieties, species, genera, have been superseded or extinguished, within longer or shorter periods, is a fact

admitted on all hands. The general principle of natural selection will account for this in the rough, maintaining as it does that fresh varieties, species, and genera better adapted to the surrounding circumstances have arisen, and by their superior adaptation unavoidably ousted the older forms. Digging down into the records of history we find a time when the Romans were supreme in the civilized world; no two consecutive years of the interval present any remarkable divergence of the prevailing conditions, yet now we may say of that Roman supremacy in the civilized world, that, like the Mastodon, it is a thing of the past.'

Torquay, May 14, 1870.