LESQUEEsra.] PALEONTOLOGY LIGNITIC FLORA SPECIES. 425 



ance at the beginning of tlie Cretaceous, are they all derived from the 

 modification of a same lower form, developed at the same or at different 

 localities under iniiueuces of the same kind ■? I do not think it possible 

 to suppose that the first leaf representative of a dicotyledonous has ap- 

 peared only at one place of the surface of the earth, nor that it has been 

 derived from a same organism over the whole world, nor that the ex- 

 ternal first causes of modification have been the same. Therefore, even 

 admitting the theory of successive transformation of vegetable types in 

 a kind of ascending scale, it would be necessary to consider as multiple, 

 local, varied in forms, the first dicotyledonous representatives. , If this 

 is true for the dicotyledonous plants, it has to be equally admitted for 

 plants of a lower type. Simple as they were, then, in their characters, 

 they did hold, as seeds do, all the future typical conformations of their off- 

 springs, resulting of influences of divers natures; but as it is the case with 

 seeds of different kinds, the result of their multiplication of growth 

 should, of course", have been represented by groups of vegetables of dif- 

 ferent characters. This would account for the diversity of floras of the 

 same epoch at distant localities, or for the isolation and dissimilarity of 

 types in the flora of two continents in synchronous formations. I believe, 

 therefore, that the disaccord remarked in the floras of geological epochs, 

 and which have been explained by displacement of floras, or what is 

 called a wandering of species, may be, in many cases at least, attributed 

 to diversity of original forms. The more we descend toward the so-called 

 primitive vegetable types, or the more simple have been the organism 

 of plants, the more easily they should have been modified under local 

 influences. A change of climate of ^ few degrees, which might have 

 caused the disappearance or extinction of some species of plants, should 

 have forced the deformation of others or the birth of new ones in a 

 proportional degree. Though the intermediate links which connect 

 ancestors and descendants in vegetable types are not always recogniza- 

 ble, even in the oldest fossil floras, it is certain that all the groups have 

 a general family-fades modified by some new and discordant forms of un- 

 accountable origin. In our Lignitic, the group of Evanstou, for example, 

 introduces to the Tertiary flora the serrate leaves, its Carya, Alnus, Be- 

 tula, &c. That of Carbon comes after with Acer, Ulmus, and other new 

 types. Have they been brought up from Greenland, from Europe, or 

 from another country, or have they appeared for the first time where we 

 find them now ? They must have had their birth at some jjlace, anyhow ; 

 and I do not see why this birthplace should not be accepted for the lo- 

 calities where the types are recognized, rather than to suppose them 

 born elsewhere and transported hereafter, adding to the problem a new 

 proposition, which renders its solution still more difficult. As said 

 above, the question is merely touched upon, as I do not wish to'take 

 ground either for or against the present system, now generally admitted, 

 of the succession of species, or of their development by modification of 

 form under any kind of influence. My purpose is merely to point out 

 the importance of the study of our ancient North American floras, repre- 

 sented by more homogeneous groups in a more regular succession, less 

 diversified by geological disturbances, and which, therefore, may afford 

 some more reliable data for consideration. The history of the vegeta- 

 tion of the earth is in intimate relation to that of the human races. 

 The proverb, "All flesh is grass," is explainable in this way : that the 

 vegetation of every epoch is in immediate relation to the synchronous 

 beings ; that vegetable life comes first and that animal life is dej^endent 

 from it; that therefore the history of the vegetation from its origin, or 

 the vegetable paleontology, should not be left aside in considering, the 

 successive phases of animal life in relation to the history of man. 



