Instead of making their appearance singly and successively, and passing imperceptibly one into another, all three groups of Vascular Cryptogams, and the Gymnosperms into the bargain, come on the stage together, in the Devonian strata; and Monocotyledons in the lower Carboniferous immediately following. There is no trace whatever of the development of any of these forms from the earlier cellular cryptogams: But [says Mr. Carruthers] the evolution of the Vascular Cryptogams, and the Phanerogams, from the green seaweeds, through the liverworts and mosses, if it took place, must have been carried on through a long succession of ages, and by an innumerable series of advancing steps; and yet we find not a single trace either of the early water forms or of the later and still more numerous dry-land forms. The conditions that permitted the preservation of the fucoids in the Llandovery rocks at Malvern, and of similar cellular organisms elsewhere, were, at least, fitted to preserve _some_ record of the necessarily rich floras, if they existed, which through immense ages, led by minute steps to the Conifer [_Gymnosperm_] and Monocotyledon of these Palæozoic Rocks. Further, these earliest plants are not generalized forms of the various tribes to which they belong, but they are as highly specialized as any subsequent representatives of the particular group to which they belong, and wherever they differ from later plants, it is in the possession of a more perfect organization. * * * * * From all which facts Mr. Carruthers thus argues: The complete absence of intermediate forms, and the sudden and contemporaneous appearance of highly organized and widely separated groups, deprive the hypothesis of genetic evolution of any countenance from the plant-record of these ancient rocks. The whole evidence is against evolution, and there is none for it.[252] Dicotyledons furnish evidence of especial value. On account of their higher organization, they are easily distinguished from both Monocotyledons and Gymnosperms; and they present features which clearly differentiate them amongst themselves. They did not make their entry till after a long interval--and their remains are therefore to be found in strata comparatively recent and better known to us than those of the older rocks. It is in the Chalk, the newest of the Secondary or Mesozoic formations, that they first exhibit themselves, and they do it in the same fashion as their predecessors. When the Dicotyledons appear in the upper cretaceous beds, representatives of the three great groups [_Apetalæ_, _Monopetalæ_, _Polypetalæ_] appear together in the same deposit. Moreover, these divisions are represented, not by generalized types, but by differentiated forms, which, during the intervening epochs, have not developed even into higher generic groups.