222 PLANTS, SEEDS, AND CURRENTS 



from the plant, either on the mud or in the water. The enormous 

 number of seedlings, only three or four inches high, that are at 

 times to be noticed under the trees affords evidence of this partial 

 vivipary. They are sometimes crowded together in thousands so as 

 to almost form a turf, and the waste must be tremendous. Should 

 the buoyant fruits drop into the water, whether into a river or into 

 the sea, they quickly proceed with the germinating process, and can 

 be carried in this condition for a great distance. Germinating fruits 

 of Laguncularia are frequent in the floating drift of the estuary of 

 the Guayaquil River in Ecuador, and I noticed them in a healthy 

 state twenty miles out at sea with the protruding hypocotyl be- 

 tween 3 and 12 mm. in length. In another locality, about three 

 miles off the coast of Ecuador, I estimated that 90 per cent, of the 

 floating Laguncularia fruits were germinating. The stranded fruits 

 of L. racemosa were frequently found by me on the beaches of 

 Jamaica, Tobago, Trinidad, etc., and they were nearly all germinating. 



The capacity of proceeding with the germinating process in sea- 

 water has been already implied, and fruits in this condition can be 

 transported far by the currents, more especially since fish do not 

 nibble at the protruding seedling. It is not likely that any floating 

 fruits could remain for more than a week or two in the sea without 

 showing the radicle; and it is quite possible that the germinating 

 fruits would survive the passage of two and a half or three months 

 in the Equatorial Current from the West Coast of Africa to the shores 

 of Brazil. That the New World derived its species of Laguncularia 

 from the West Coast of Africa before the emergence of the Panama 

 Isthmus seems probable. 



The fruits can withstand drying when detached from the tree in 

 the entire condition. Five green non-germinating fruits were placed 

 in sea-water in Jamaica after being allowed to dry in the air for 

 nearly two weeks. A fortnight afterwards three were germinating 

 healthily afloat. 



Comparison op the Shape and Dimensions op the Fruits op Laguncularia 

 racemosa op the West Indian Region and op the Panama Isthmus with 

 those op the Laguncularia of the Estuary op the Guayaquil River and 

 of the neighbouring coasts of Ecuador. 





Form, etc. 



Length 



Breadth 



Laguncularia racemosa 

 of the West Indies, etc. 



Broadens out into 

 shoulders near the top. 

 Ribs and wings more promi- 

 nent. 



17 mm. 



8 to 9 mm. 



Ijaguncularia of Ecua- 

 dor. 



Becomes narrower near 

 the top. Ribs and wings 

 less prominent. 



18 to 19 mm. 



6 to 7 mm. 



In my book on Plant Dispersal (p. 498) reference is made to the 

 circumstance that the Laguncularia tree of the Guayaquil estuary 

 and of the neighbouring coast swamps of Ecuador has a fruit differ- 



