FOREIGN DRIFT OF THE TURKS ISLANDS 135 



the foreign drift reaches this small group. It is a tree of the Amazon 

 delta and of the Middle Amazon, growing in woods on the river- 

 bank. It is accordingly something more than an estuarine tree, 

 since it extends far up the great river and has been found at Teffe 

 some distance above the confluences of the Negro and the Madeira 

 with the main stream. The latest reference I have found to the 

 distribution of this tree is that given by Stapf in Morris's paper of 

 1895. We learn from the Index Kewensis that the genus holds 

 about ten known species, of which nine are Brazilian and one is 

 found in the Guianas. Probably Sacoglottis amazonica is the only 

 species that is dispersed by the currents; and it is pointed out in 

 Chapter IV. that the limitation of this tree to the New World appears 

 to be entirely a question of the arrangement of the currents, which 

 would readily transport the fruits in a sound and effective condition 

 from tropical West Africa to Brazil, but not from the tropics of the 

 New World to West Africa. 



Before dealing with these fruits from the standpoint of their 

 fitness for dispersal by currents, I will observe that they were charac- 

 terised by Morris as possessing " ideal qualities " as drift fruits, 

 their great buoyancy being due, as he points out, to numerous closed 

 cavities or resin-cysts. The typical drift fruit, as he explains, has 

 lost the outer fleshy covering of the fresh fruit. He found that two 

 of the normal five cells of the fruit were usually suppressed. His 

 account is illustrated by excellent figures of the fruit. 



They presented themselves to me in West Indian beach-drift 

 as oblong woody fruits, about two inches long, and usually two- 

 seeded. After the detachment of the ripe fruit from the tree, the 

 outer fleshy covering evidently dries up and forms a dark-brown 

 skin, which is soon lost in the " wear-and-tear " of the drift, and is 

 only to be observed with fruits that have not travelled very far from 

 the parent plant. When stripped of the outer skin the drift fruit 

 presents a remarkable appearance on account of the rounded 

 " bulgings " on the surface, which correspond to the empty resin- 

 cavities beneath. It is in this bared condition as light-coloured 

 warty ligneous fruits that they generally occur in West Indian 

 beach- drift, the outer dark skin, two or three millimetres in thickness, 

 having been lost, as above stated, in the " wear-and-tear " of sea 

 transport. The two seeds lie in the centre of the fruit. They 

 occupy long cells two-thirds of the fruit's length, but appear to be 

 perfectly protected against the penetration of sea-water. Any 

 weak place in the equipment of the seeds for traversing an ocean 

 unharmed would be expected rather in the inherent inability of 

 the seed to retain its germinative capacity for a period sufficiently 

 long than in any defect in the protection afforded by the fruit-case. 



It is only at the extreme south-east corner of the West Indian 

 region, namely, in the islands of Trinidad and Tobago, that these 

 drift fruits present themselves on the beaches in a more or less 

 entire state, that is to say, with the outer skin in a more or less 

 perfect condition. The bared state, as Morris points out, is the typical 

 condition of the drift fruit. In Jamaica they are always bared, 

 and the same may be said of those in the beach-drift of the Turks 



