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THE AMERICAN NATURALIST [Vol. XL VI 



The recent rapid development of our knowledge of the 

 structures of fossil plants is familiar to botanists, con- 

 stituting as it does one of the most remarkable chapters 

 in the history of our science. This has been due not only 

 to the elaboration of a technique for sectioning petrifac- 

 tions, but also to the inclusion of Ihe vascular system 

 among the morphological material that is recognized to 

 be significant in conclusions concerning phylogeny. From 

 the standpoint of paleobotany, the vascular system is its 

 most valuable asset for vascular plants, for its chances 

 of preservation exceed those of any other structures ex- 

 cept the seed, and its significance in phylogeny is far 

 more apparent and extended than that of the seed. As a 

 result of this paleobotanical connection, the phylogeny of 

 the vascular groups can be made now a resultant of com- 

 parative structures and actual history. Many an old 

 phylogeny, based upon the comparative structures of ex- 

 isting plants alone, has been contradicted by history, 

 which, in the nature of things, must furnish the final 

 check upon any proposed phylogeny. 



The topic of this paper is really an invitation to indi- 

 cate some of the recent reactions of modern paleobotany 

 upon the phylogenies of vascular plants. The title in- 

 cludes taxonomy, but in so far as this deals with great 

 groups, defined or discovered, it is covered by the state- 

 ments concerning phylogeny. So far as it deals with the 

 recognition of individual forms, it is clear that paleo- 

 botany must learn to recognize the relationships of fossil 

 plants, or there will be no reliable taxonomy or phy- 

 logeny. So long as paleobotany depended upon the form 

 resemblances of detached organs, there could be no tax- 

 onomy in the real sense. It was merely a cataloguing of 

 plant material. But when it learned to uncover struc- 

 ture, it began to establish a real taxonomy. The contri- 

 butions of paleobotany to taxonomy, therefore, may be 

 summed up in the statement that it has begun to extend 

 our schemes of classification into the ancient floras ; that 

 this has resulted in a far truer view of the great groups 



