212 PLANTS, SEEDS, AND CURRENTS 



to find a reference to it in any other island, though Sloane states that 

 it grows all over the West Indies. From the fact that the fruits, 

 which possess considerable floating powers, are significantly absent 

 from the drift heaped up on the beaches of the Turks Islands, it 

 would seem that the tree does not grow in the islands which are 

 the source of much of this drift, namely, San Domingo, Porto Rico, 

 and the neighbouring Leeward Islands. Whilst the fruits are 

 characteristic of the drift of the Jamaican beaches, being thrown 

 back on the coast after being brought down by the rivers, as in the 

 vicinity of the mouths of the Black River, the Cabarita, and the 

 White River, they did not come under my notice in the beach-drift 

 of Grenada, Tobago, and Trinidad. They would, therefore, appear 

 to be unrepresented in the drift of the Orinoco and the Amazon, 

 since it is stranded in quantity on those islands ; and one may note in 

 passing that Hart does not mention the tree in his " Herbarium List " 

 of the Trinidad flora. It is, however, shown below that the same tree 

 evidently exists on the upper reaches of the Guayas River in Ecuador, 

 and that an unidentified species of the genus grows in quantities near 

 rivers on the lower eastern slopes of the Ecuadorian Andes. 



Whilst its limited distribution in the West Indies may be partly 

 due to the little power of preserving the germinative capacity of the 

 seed in the floating fruit, a matter discussed below, it is evident that 

 questions quite apart from those relating to means of dispersal are 

 here raised. According to the Index Kewensis (up to 1905) the genus 

 holds four species referred respectively to Peru, Panama, the West 

 Indies, and Guiana. But a mere list of species with their habitats 

 conveys no notion of the role plants of this genus play in tropical 

 South America. It would appear that these trees are especially 

 at home on the lower slopes of the Equatorial Andes on the Pacific 

 and Atlantic sides, as well as along the upper reaches of the rivers in 

 that region. Spruce found Grias trees in the Chimborazo forests 

 extending up to 3500 feet above the sea (Notes of a Botanist on the 

 Amazon and Andes, II., 286; 1908). Mr. A. R. Wallace, who edited 

 Spruce's book nearly half a century after the traveller returned from 

 South America, subsequently sent to the Kew Bulletin (1909, p. 216) 

 some additional notes made by Spruce on the riverside vegetation 

 of the Upper Amazon. We there learn that a species of Grias almost 

 entirely composed the forest in places on the Pastasa River, a tribu- 

 tary of the Maranon branch of the Amazon, on the lower eastern slopes 

 of the Ecuadorian Andes. The specific identity was not determined 

 in these cases ; but I may add that on comparing some of my Jamaican 

 specimens of the fruit of Grias cauliflora with fruits gathered by me 

 some years before from the floating drift of the Guayaquil River in 

 Ecuador, the two kinds could not be distinguished from each other. 

 These floating fruits formed a feature in the drift of this Ecuadorian 

 estuary, and evidently were derived from the upper reaches of the 

 river. Specimens of them sent by me to the Kew Museum have been 

 labelled Grias cauliflora by those in charge. 



Looking at the foregoing facts of distribution, it seems fair to 

 assume that this genus was once far more widely spread over the 

 West Indies than it is at present. It is doubtless a remnant of a 



