But such a serial arrangement would give a totally false idea of the way the different types have arisen; and any conclusion based on the existence of such a series might very well be entirely erroneous, for the fact that such a series exists bears no relation to the order in which its members have appeared.” (_Op. cit._, pp. 12, 13.) Such facts must give us pause in attaching undue importance to phenomena like the occurrence of a gradual complication of sutures in the Chalk Ammonites, particularly as parallel series of perfectly similar sutures occurs “by convergence” in the fossil Ceratites, which have no genetic connection with the Ammonites. (Cf. Woods’ “Palæontology,” 5th ed., p. 16.) But, if even mutational and specific intergradents are not sufficient evidence of common ancestry, what shall we say of a discontinuous series, whose links are separate genera, orders, or even classes, instead of species. Even the most enthusiastic transformist is forced to admit the justice of our insistence that the gaps which separate the members of a series must be reduced from differences of the generic, to differences of the specific, order, before that series can command any respect as hypothetical “genealogy.” “You will have observed,” says F. A. Bather, “that the precise methods of the modern palæontologist, on which this proof is based, are very different from the slap-dash conclusions of forty years ago. The discovery of _Archæopteryx_, for instance, was thought to prove the evolution of birds from reptiles. No doubt it rendered that conclusion extremely probable, especially if the major promise—that evolution was the method—were assumed. But the fact of evolution is precisely what men were then trying to prove. These jumpings from class to class or from era to era, by aid of a few isolated stepping-stones, were what Bacon calls anticipations “hasty and premature but very effective, because as they are collected from a few instances, and mostly from those which are of familiar occurrence, they immediately dazzle the intellect and fill the imagination.” (_Nov. Org._, I, 28.) No secure step was taken until the modern palæontologist began to affiliate mutation with mutation and species with species, working his way back, literally inch by inch, through a single small group of strata. Only thus could he base on the laboriously collected facts a single true interpretation; and to those who preferred the broad path of generality his interpretations seemed, as Bacon says they always “must seem, harsh and discordant—almost like mysteries of faith.” ... Thus by degrees we reject the old slippery stepping-stones that so often toppled us into the stream, and, foot by foot, we build a secure bridge over the waters of ignorance.” (_Science_, Sept. 17, 1920, pp. 263, 264.)