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THE AMERICAN NATURALIST [Vol. XL VI 



general at the present time would be lacking in logical or 

 adequate explanation but for the facts which have been 

 brought to light by the study of fossil plants in regard to 

 distribution in the past. Many such instances might be 

 cited, but for the purposes of this symposium a few of 

 the most striking only need be recalled to serve as con- 

 crete examples of the general abstract propositions. 



In the earlier part of the last century, when the science 

 of paleobotany was in its infancy, and much that we now 

 know about living plants had not been learned, numerous 

 remains of coniferous trees were found in Europe and 

 elsewhere in the Old World, in deposits of relatively 

 recent geologic age. For the most part these remains 

 were either identified as living genera or were given 

 generic names designed to indicate their nearest appar- 

 ent relationships with such (Pinites, Taxites, Arauca- 

 rites,etc). Other similar remains, however, which could 

 not be satisfactorily compared with any living ones, were 

 given new generic names. Among these latter may be 

 mentioned certain small cones associated with leafy 

 twigs, which were assumed at the time to represent an 

 extinct coniferous genus. Large areas of the New World, 

 however, were yet unexplored and many hitherto un- 

 known living genera were awaiting discovery and de- 

 scription. One of these was Sequoia, a genus of two 

 species only, confined in their distribution to scattered 

 groves on the western coast of the United States. Ecol- 

 ogy was an unknown science when these groves were dis- 

 covered, but the relatively limited number of the indi- 

 vidual trees, and their geographic isolation, at once 

 attracted attention and aroused interest and discussion 

 in regard to their ancestry and the phenomenon of their 

 peculiar distribution. Paleobotany supplied the desired 

 information. When the generic characters of Sequoia 

 were made known they were seen to be identical with 

 those of the supposed extinct fossil coniferous genus of 

 the Old World. Further than this, however, similar re- 

 mains, comprising numerous different species, were sub- 



