198 PLANTS, SEEDS, AND CURRENTS 



but it would seem to belong to a late stage in the plant- stocking of 

 isolated small islands. From the circumstance that Mr. Lansing 

 recorded it from only one of the Florida sand-keys and regarded it 

 as introduced, it would not appear to be one of the early plants that 

 establish themselves on newly formed islets in these seas. 



In my notes I have only recorded it from four of the islands of the 

 Turks Group, namely, on Grand Turk, Long Cay, Cotton Cay, and 

 Salt Cay; but where found it is usually abundant. Amongst other 

 localities on Grand Turk it grows in quantity in the interior of the 

 low-lying level region of the southern half of the island, where on 

 a sandy soil it is associated with shrubs or small trees, as the case 

 may be, of Bontia daphnoides, Dodoncea viscosa, Euphorbia vaginulata, 

 Sophora tomentosa, etc. ; but here, as in other parts of the island, 

 it extends in places to the beach. It thrives on the edge of the rocky 

 plateau of Long Cay on the leeward side, where it is associated with 

 Genipa clusiifolia, the Seven-year Apple. In Cotton Cay it grows in 

 dense thickets on the rocky surface of the wind-swept eastern ex- 

 tremity of the island, the Seven-year Apple growing under its lee; 

 but the constant exposure to the strong trade-wind has compelled 

 it to assume a semi-prostrate, straggling habit of growth. Its be- 

 haviour in the Turks Islands closely corresponds with that in the 

 rest of the Bahamian region, where it grows not only on the sandy 

 and rocky shores, but on the dry plains in their rear, and is often 

 associated in coastal thickets with Genipa clusiifolia (Harshberger, 

 Millspaugh, etc.). 



The fruits are of regular occurrence amongst the smaller drift of 

 beaches wherever the plants grow on the coast ; and not infrequently 

 they may be found germinating in the drift washed up by the waves, 

 together with seedlings derived from the stranded fruits. The 

 fallen fruits lie in numbers under the trees lining the beach, and they 

 could be easily swept off by the waves at the higher tides. They 

 germinate in numbers on the ground beneath the trees, and numerous 

 seedlings are to be seen striking into the sandy soil. This inclination 

 to rapid germination on the soil would militate against the chances 

 of effective dispersal by currents, since seeds that germinate easily 

 would, as a rule, be imperfectly protected against the penetration 

 of sea-water, and in many cases these fruits, when swept off the 

 beaches by the waves, would be in the early stage of germination. 



We come now to the methods of dispersal. The purplish, fleshy 

 fruits, 15-20 mm. long, at once suggest the agency of frugivorous 

 birds; and it is in this fashion that Hemsley considers the over- 

 seas dispersal of the plant may be explained (Chall. Bot. Intro., p. 49). 

 In this connection it is noteworthy that Coccoloba laurifolia, one 

 of the species that come next to C. uvifera amongst the West Indian 

 species with wide ranges, is known in Florida as the Pigeon Plum 

 (Fawcett and Rendle). Pigeons would probably be effective agents 

 of local dispersal or of inter-island distribution across narrow tracts 

 of sea; but it is very doubtful whether they would be effective 

 for long ocean traverses that could not be accomplished by a bird 

 in a few hours. The defects in structure that unfit the fruit for 

 prolonged flotation in the sea, as below described, would also render 



