or 
oe Le er CRETACEOUS FLORA, 
degree of organization than another. And also, in the large number of vegetable 
remains of the lower division of plants, none have been found in the long series of 
ancient vegetables, whose characters would indicate a tendency to a transition to a 
«a higher order. Some ferns of the Trias and the Lias, even of the Carboniferous, 
are by their outlines, like dicotyledonous leaves, but their nervation is always far 
different, and, moreover, as said above, the likeness of a leaf can not by itself indi- 
cate a relation in the characters of a plant, as in passing for example, from a fern to 
a dicotyledon the whole plant has to be modified, the structure of the stem, the 
wood, the flowers, fruits, ete. Evolutionists may trace the derivation of a species 
of mammals from one to another, but they can not look for such transitional forms 
between a saurian and a mammal; and it is a difference of this kind which exists 
between the dicotyledons and the lower series of vegetables predominant from the 
origin of the land plants to the Wealden. 
But more. If the change had proceeded by slow degrees of modification of one 
species, the results would be, of course, a great uniformity or an affinity of parentage 
noticeable in the derived types. That is certainly not the case for the flora of the 
Dakota group, as it is known at the present time, has its dicotyledonous species 
referable to the three great divisions of the present dicotyledonous flora; the Apeta- 
lew, the Gamopetalee and the Dialapetalee. Of the first, it has the Amentacew with 
species of the genera Myrica, Betula, Alnus; the Cupuliferee with Fagus, Quercus, 
Salix, Populus, Platanus, Liquidambar; the Moree with Ficus; the Proteacee with 
Proteoides, Todea, Lomatia; the Lauracee with Laurus, Persea, Sassafras, Cinnamomum, 
Oreodaphne; the Aristolochieew with Aristolochia. Of the second, it has the species of 
Diospyros in the Diospyrinee and of Andromeda in the Ericacee. Of the third, it has 
the Araliacee with a number of species of Aralia, and of Hedera; the Ampelidee with 
Cissus; the Polycarpee with Magnolia, Liriodendron, Liriophyllum, Anona anda number 
of species of Menispermacee ; the Malvacee with Sterculia; the Tiliacee with Greviopsis ; 
the Aceracee with Acerites, and especially Sapindus; the Frangulacee with Ilex, 
Palinurus, Rhamnus; the Terebinthinew, with Juglans and Rhus; the Rosifloree with a 
Pyrus and a Prunus; then species of the Leauminosee with a number of leaves 
assigned to genera whose affinity with plants of the present epoch is not distinctly 
marked. How is it possible toadmit or even suppose that plauts referable to such a 
number of genera distributed in divers families of the three essential subdivisions of 
the dicotyledons might have originated by gradual modifications of one or more 
species of the inferior classes of plants, to which, as remarked above, it has been 
impossible to find any kind of analogy, and this, too, during the time of transition 
between two consecutive periods, the Urgonian and the Cenomanian? 
