364 SKETCH OF PALEOBOTANY. 



present life as a product of development. Paleozoology has already 

 thrown a flood of light upon the true nature of animal life as it now ex- 

 ists, and now paleobotany is rapidly coming to the aid of those who have 

 hitherto so long groped in darkness relative to the origin, development, 

 and distribution of the plant life of the globe. 



III.— SCOPE OF THE PRESENT PAPER. 



With the second of these objects the present work is only incident- 

 ally concerned, its chief aim being to secure, so far as its influence ex- 

 tends, the better realization of the first. Still, it cannot be denied that 

 a considerable degree of mutual dependence subsists between the bio- 

 logic and the geologic standpoints. To understand the true force of the 

 facts of paleobotany as arguments for geology it is essential that their 

 full biologic significance be grasped. It has therefore been deemed 

 proper, in this introduction to the several tabular and systematic state- 

 ments which will make up the bulk of the volume and bear chiefly upon 

 the geological aspect of the subject, to consider certain of the more im- 

 portant biologic questions, in addition to the specially geologic ones, 

 and to discuss, from an historical and developmental standpoint, some 

 of the leading problems of modern phytology. 



TV— ISTBEI) OF A CONDENSED EXHIBIT. 



First of all it must be insisted upon that, notwithstanding the large 

 amount of work that has been done in paleobotany and the somewhat 

 formidable literature which it possesses, the present state of the science 

 is far from satisfactory when regarded as a guide to the attainment of 

 either of the ends above mentioned. Its value, as compared with that 

 of paleozoology, in the determination of the age of formations in which 

 vegetable remains are discovered is very small, yet it may well be asked 

 whether the habit of discounting the testimony of fossil plants, acquired 

 at a time when much less was known than now, may not have been con- 

 tinued to an extent which is no longer warranted by the present state 

 of our knowledge. Whether this be so or not, it is at least certain that 

 the real present insufiSciency of this department of paleontology as an 

 exact and reliable index to geologic succession is largely due to the ex- 

 ceedingly fragmentary and desultory character of the science, consid- 

 ered as a body of truth, and that a proper and careful collation and sys- 

 temization of the facts already in the possession of science will add in 

 a high degree to their value iu this respect. It was this consideration, 

 so obvious to me from the beginning of my investigations in paleobot- 

 any, that moved me to undertake the compilation of this work, and it 



