We ought only to look for a few links, and such assuredly we do find--some more distantly, some more closely, related to each other; and these links, let them be ever so close, if found in different stages of the same formation, would, by many palaeontologists, be ranked as distinct species.

But I do not pretend that I should ever have suspected how poor was the record in the best preserved geological sections, had not the absence of innumerable transitional links between the species which lived at the commencement and close of each formation, pressed so hardly on my theory.
ON THE SUDDEN APPEARANCE OF WHOLE GROUPS OF ALLIED SPECIES.
The abrupt manner in which whole groups of species suddenly appear in certain formations, has been urged by several palaeontologists--for instance, by Agassiz, Pictet, and Sedgwick, as a fatal objection to the belief in the transmutation of species.

If numerous species, belonging to the same genera or families, have really started into life at once, the fact would be fatal to the theory of evolution through natural selection.

For the development by this means of a group of forms, all of which are descended from some one progenitor, must have been an extremely slow process; and the progenitors must have lived long before their modified descendants.

But we continually overrate the perfection of the geological record, and falsely infer, because certain genera or families have not been found beneath a certain stage, that they did not exist before that stage.