Seite - 354 - in The Origin of Species

354 ORIGIN OF SPECIES / consecutive record of their modifications could be preserved L-in any one formation. Very many of the marine inhabitants of the archipelago now range thousands of miles beyond its confines ; and anal- ogy plainly leads to the belief that it would be chiefly these far-ranging species, though only some of them, which would oftenest produce new varieties ; and the varieties would at first be local or confined to one place, but if possessed of any decided advantage, or when further modified and improved, they would slowly spread and supplant their parent-forms. When such varieties returned to their ancient homes, as they would differ from their former state in a nearly uniform, though perhaps extremely slight degree, and as they would be found embedded in slightly different sub-stages of the same formation, they would, according to the principles fol- lowed by many palaeontologists, be ranked as new and distinct species. I If then there be some degree of truth in these remarks, we \ have no right to expect to find, in our geological formations, I an infinite number of those fine transitional forms which, on I our theory, have connected all the past and present species Lof the same group into one long and branching chain of life. rWe ought only to look for a few links, and such assuredly I we do find—some more distantly, some more closely, related 1 to each other; and these links, let them be ever so close, if \ found in different stages of the same formation, would, by Lmany palaeontologists, be ranked as distinct species. But I k 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 sud- denly appear in certain formations, has been urged by several palaeontologists —for instance, by Agassiz, Pictet, and Sedg- jvick—as a fatal objection to the belief in the transmutation