RHIZOPHORA MANGLE 



109 



mud on the margins of the lagoons, in the places removed from the 

 lagoons where the saline mud dries on the surface in the sun, in the 

 neutral ground between the sandy beach and the mud-flat where the 

 soil is loamy and beach plants mingle with those of the mud-flats,- 

 or, lastly, on the borders of the great inland fresh-water swamps, 

 where they come in touch with the plants of the Great Morass. In 

 all these stations they have different associates : herding at one time 

 with Rhizophoras and Laguncularias in the swamps; at another 

 growing with Salicornias on the soft mud-flats; at another with 

 Jacquinia armillaris, Conocarpus erectus, etc., where the saline mud 

 hardens on the surface in the sun ; at another time side by side with 

 beach plants like Coccoloba uvifera, Dodoncea burmanni, and Ernodea 

 littoralis, where the soil is loamy near the beach; and at another 

 time amidst the tall Sabal palms (S. umbraculifera) and the Cyperacece 

 which mark the outskirts of the inland region of fresh- water swamps. 

 If we except Conocarpus erectus, there is no plant in the Salt Lake 

 district that displays so much adaptability to the various conditions 

 as Avicennia nitida. 



Conocarpus erectus is similarly associated here with the mangroves 

 at the borders of the lagoons, with the plants of the exposed mud- 

 flats, and with those of the sandy beach ; but its powers of adaptation 

 are not so conspicuous on account of its being much less frequent 

 than Avicennia nitida. Its adaptability to different stations is 

 discussed more in detail in the separate treatment of the plant. 



Several other plants occur in this district, but they are usually 

 not common enough to give character to the vegetation. One may 

 refer, however, to the Silver Thatch palm (Thrinax argentea), a small 

 palm, three to nine feet high, which is certainly characteristic of the 

 neutral ground between the mud-flats and the sandy beach on the 

 seaward side and the inland swamps in their rear. Portulaca hali- 

 moides, an interesting little plant with woolly flowers and only two 

 or three inches high, grows in places on the salt white mud, especially 

 where the ground, though moist beneath, is baked on the surface by 

 the sun's heat. Jacquinia armillaris (L.) is a small tree or shrub 

 that is very common on the saline mud of the flats, growing gregari- 

 ously and exhaling from its flowers a penetrating odour like that of 

 bitter almonds. This is J. barbasco of Mez (Das Pflanzenreich, 

 Theophrastacece, 1903). It is a littoral plant widely spread in the 

 West Indies. Its hard seeds, which are 5 mm. in length, have no 

 buoyancy, and are probably dispersed by birds, though the dryish 

 berry would not seem to be especially attractive. 



Summary 



1. As supplementing his observations on Rhizophora in the Pacific 

 islands, the author adduces additional facts from other sources to 

 confirm his previous conclusion that the lapse of a period of nine or 

 ten months between fertilisation and the fall of the seedling is typical 

 of the genus (p. 96). 



2. He presents data from his West Indian experiments to show that 

 Rhizophora seedlings, after detachment from the tree, can at times 



