354 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1912. 



in which they are most made use of in this connection, are so indefi- 

 nite, mdistinct, and um-eliable that they can not be allocated bio- 

 logically with even reasonable certainty, and hence are of little or 

 no value. As a matter of fact hardly anjrthing could be further 

 from the truth, and it can be confidently stated that it makes not 

 the slightest difference to the stratigraphic geologist whether the 

 fossils upon which he most relies are named at all, so long as the hori- 

 zon whence they corsie is known and they are clearly defined and 

 capable of recognition under any and all conditions. They might 

 almost as well be referred to by number as by name, so long as they 

 fill the requuvments above demanded, tliougli of course every strati- 

 graphic paleontologist seeks to interpret to the very best of his 

 knowledge the fossils he studies. He may — doubtless often does- 

 make mistakes in his attempts to understand them, but his errors 

 are undoubtedly fewer than he is not infrequently charged with. 

 His faculty of observation is rendered acute from the close study of 

 the restricted and often fragmentary material available, and he has 

 learned to see and make use of characters which are often overlooked 

 or wholly neglected by the botanist. The latter, even when he has 

 before him the complete living plant, including root, stem, and foliar 

 and reproductive organs, sometimes experiences difficulty in cor- 

 rectly placing his subject, and, to judge from some recent work, 

 there are paleobotanists who study only the internal structure of 

 fossil plants and yet are beset with extreme difficulty in interprethig 

 their biological significance. 



It may then be taken as settled that the needs of the stratigraphic 

 geologist will be met if he is supplied with a series of marks or tokens 

 by which he may unfailingly identify the- various geological horizons 

 with which he deals, while to the historical geologist who makes use 

 of fossils in unravehng the succession of geological events the correct 

 biological identification is of the greatest importance, for upon this 

 rests his interpretation of the succession of faunas and floras that 

 have inhabited the globe. As the late Dr. C. A. "V^^nte has said, 

 " If fossils were to be treated only as mere tokens of the respective 

 formations in wliich they are found, theii' biological classification 

 would be a matter of little consequence, but their broad signification 

 in historical geology, as well as in systematic biology, renders it 

 necessary that they be classified as nearly as possible in the manner 

 that living animals and plants are classified." 



While it is in no way desired to overloolc or underestimate the 

 biologic value of such fossil plants as have fortunately retained their 

 internal structure in condition for successful study, it is probably 

 safe to say that their value to geology as compared with the impres- 

 sions of plants is as 1 to 1 ,000, and had we only the former there 

 never could have been developed the science of stratigraphic paleo- 



