IgIo] BERRY—EOCENE FLORA IN GEORGIA 207 
Pisonia, and Sapindus have become adapted for dispersal through 
the agency of ocean currents, by specialization of their fruits or 
seeds, which have developed air chambers or woody husks for 
buoyancy, and practically impervious seed coverings for the 
exclusion of sea water from their vital parts. Everyone is familiar 
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Fic. 2.—Sketch map showing the approximate shore line of the middle eocene 
sea in southeastern North America, _ 
with the extreme specialization of the mangrove, which sends its 
germinating plantlets out into the world fully prepared to anchor 
themselves in water of the required depth, but the comparable 
specializations of the other members of these floras, though less in 
degree, are almost as effective, judging by the present geographical 
distribution of these genera, so that ocean currents must play a con- 
_ Siderable réle in distribution, despite the contrary opinion of DE 
