SOME ANCESTOKS OF THE PERSIMMON 19 



America, where the Miocene records are very incompletely pre- 

 served, the persimmon is recorded from Montana^ Colorado, Cali- 

 fornia, and Oregon. The leaves of at least two species are pre- 

 served in the late Miocene upland lake basin of Florissant in the 

 Rocky Mountains of Colorado. Specimens of Diospyros calices 

 from the Miocene of Switzerland are shown in figs. 5 and 6. 



The Miocene period was followed by the Pliocene, a time during 

 which the American deposits appear to have been unfavorable, 

 either because of their character or location, for the preservation 

 of fossil plants, since practically none have been discovered. In 

 Europe on the contrary, there were great fluctuations of the medi- 

 terranean sea which at one time covered most of southeastern 

 Europe with its shallow waters. The climate was consequently 

 equable and humid and the shores were well wooded, as is clearly 

 indicated by the great abundance of fossil plants which were pre- 

 served. The persimmon continued to be an abundant element in 

 these Pliocene floras, and no less than eight different species of 

 Diospyros have been reported from deposits of this age. The 

 localities include Italy, Spain, France and Austria, one of the 

 French species being indistinguishable from our existing Diospyros 

 virginiana. A fortunately preserved Pliocene deposit on the 

 island o£ Java shows that then as now, Diospyros was a prominent 

 element in the Malayan flora. 



What happened at the close of the Pliocene, we can only 

 conjecture, since we have no Pleistocene records of Diospyros. 

 We know that their range was gradually restricted through cool 

 northern climates, and by the gradual development of the plains 

 type of country due to continental growth and to the elevation of 

 mountain ranges which shut off the moisture laden winds. With 

 the subsequent advance of the glaciers southward over Europe 

 in Pleistocene time, and the glaciation in the mountains, Pyrenees, 

 Alps, Carpathians and others, which with the Mediterranean sea 

 shut off the retreat of the numerous Tertiary forms, Diospyros 

 fared but ill on that continent and most of the species became 

 exterminated. In America and Asia, a congenial habitat spread 

 far to the southward of the ice-front and there were no dangerous 

 mountain glaciers across their paths, consequent^ the persim- 



