]38 BERRY— LOWER EOCENE FLORA OF [April 25, 



the Mississippi Gulf either during the Cretaceous-Eocene interval, 

 during the Midway or during the Midway-Wilcox interval. While 

 the time available for this northward dispersal was thus sufficiently 

 long to account for the migration of even the most slowly spreading 

 forms a short statement on the adaptations and agencies of this 

 dispersal is not without interest. The Wilcox genera with winged 

 fruits or seeds are Engelhardtia, Paraengelhardtia, Dodoncsa, Paliii- 

 'rus, Fraxmus and the Proteacese and Malpighiaceae. None of these 

 are capable of long flights except those of the last two families and 

 these during high winds might readily be carried for miles along 

 coasts, although it is doubtful if they could have crossed great 

 stretches of open water, even through the agency of a West Indian 

 hurricane. The heavier winged fruits such as those of Engelhardtia, 

 Paraengelhardtia, Paliurits, Dodoncea and Fraxinus float readily, 

 although as far as I know there is no experimental data to show 

 how long they float in oceanic waters without losing their vitality. 

 Certainly Dodoncea has reached the Bermudas in recent times 

 through the agency of the Gulf Stream. Among the Wilcox forms 

 more or less adapted for floating the following genera may be enu- 

 merated : Nipadites, Canna, Taxodiiim, Pisonia, Sapindns, Sterculio- 

 carpus, Trapa, Avicennia, Solanites, Exostema and the Combretacese. 

 Among the foregoing Canna, Taxodium, Trapa and Exostema are 

 scarcely adapted for sea voyages while on the other hand, Nipadites, 

 Sapindns, Sterculiocarpns, Avicennia and the Combretacese are sin- 

 gularly adapted for dispersal by ocean currents and would be in the 

 van of forms colonizing the shores of the transgressing Wilcox sea. 



A large number of the Wilcox genera had fleshy or drupaceous 

 fruits and formed the dietary of both mammals and birds. Among 

 these the following may be mentioned: Myrica, Ficns, Coccolohis, 

 Magnolia, Anona, Asimina, Chrysobalanus, Simaruba, all the Laura- 

 cese, Ilicacese, Celastracese, Myrtaceae, Ebenaceze, Sapotacese, Melia- 

 cese, Euphorbiacese, Anacardiaceae, Zizyphus, Gnettarda, Citharexy- 

 lon, Cordia, Osmanthus, Icacorea, Rhamnus and Reynosia. Many 

 of these have crustaceous stones that pass uninjured through birds 

 or are voided with their vitality unimpaired and these could undoubt- 

 edly be carried long distances over seas. Even in the case of soft 

 seeds like those of a large number of the Leguminosce it has been 



