234 



moderately humid climates (which are the only climates I have 

 thus far experienced). Just how and why fluctuations of water- 

 level affect vegetation is a problem which belongs to ecology 

 rather than to phytogeography, and it would require too much 

 space to discuss it here. 

 University, Ala. 



FOSSIL FLOWERS AND FRUITS 



By T. D. a. Cockerell 



The Miocene shales at Florissant, Colorado, are remarkably 

 rich in flowers and fruits, some of which have already been de- 

 scribed. Many others have remained unpublished, because I 

 found it extremely difficult to determine their generic relation- 

 ships with any degree of certainty. Some years ago, I took a 

 series to Cambridge University in England, where they were 

 much admired, but eventually returned to me with the remark 

 that no one there felt able to describe them. I have been very 

 unwilling to publish species of " Antholithes," " Carpolithes," etc., 

 which could not even be referred definitely to particular families ; 

 but it is possible that by ignoring these specimens we may be 

 missing some important evidence. Tertiary plants are nearly 

 always referred to living genera, and it is at least certain that 

 few if any distinct genera of plants have originated since the 

 Miocene. It is quite a different question, however, whether any 

 have become extinct since that time, and indeed it is practically 

 certain that many genera have disappeared during the Tertiary. 

 We know genera like Sequoia, which formerly were widespread 

 and abundant, but now are restricted to small areas. The 

 important genus Ginkgo would have disappeared entirely had it 

 not been taken into cultivation. It is therefore quite reasonable 

 to look for extinct genera in the Miocene, and if these really 

 exist among our fossils, it is probable that the fruits and flowers 

 will best indicate them. For such reasons as these it may be 

 worth while to publish descriptions of unclassified flowers and 

 fruits, which may be introduced as " Antholithes" and " Car- 

 polithes," and perhaps correctly classified at some later date. 



