154 PLANTS, SEEDS, AND CURRENTS 



Much depends on these points, since fruits that were entire and 

 showed but little signs of* long exposure to the sea could scarcely 

 have accomplished the passage from the New World. 



It is interesting to note the fact referred to by Hemsley (Chall. 

 Bot., IV., 278, 301) that Martins raised plants from seeds of Cassia 

 fistula cast ashore in the pod at Montpellier in the south of France. 

 Hemsley cites this case as one of the instances where plants have 

 been raised in Europe from seeds that have traversed the Atlantic. 

 On this view the pod must have been carried through the Straits of 

 Gibraltar into the Mediterranean after its ocean traverse. Here, 

 again, much would depend on the condition of the stranded fruit 

 when determining its probable source. It would seem safer, indeed, 

 to look for a source much nearer home than the American side of the 

 Atlantic ; for instance, in Egypt, where the tree has long been widely 

 spread, since such pods might have been brought down to the sea in 

 the Nile drift. At all events, the observations of Martins at Mont- 

 pellier and of myself in the Turks Islands indicate that the pods of 

 Cassia fistula can carry sound seeds across considerable tracts of 

 sea; but the data at my disposal, whilst indicating the possibility 

 that the pods can be transported from the New World to the shores 

 of Europe by the currents, leave the question as to the condition of 

 the seeds unanswered. There is a lack of information concerning 

 the actual facts recorded, and for this reason a suspension of judgment 

 may be necessary. 



It should be remarked that whilst the pods of Cassia fistula are 

 characteristic of West Indian beach-drift, there seems to be but 

 little mention of their occurrence in the drift of tropical beaches in 

 the Old World. Let us take, for instance, the Indian Archipelago 

 in its most comprehensive sense as including the whole region between 

 south-eastern Asia and Australia. This region is regarded as one of 

 the principal homes of the tree, and yet its fruits seem rarely to have 

 attracted the notice of observers of the drift. Thus they are not 

 named in Gaudichaud's description of the drift of the Molucca Sea 

 as quoted by Hemsley {Chall. Bot., IV., 279). Schimper does not 

 mention them in his account of the drift of the Java Sea and of the 

 coasts of Java (p. 160). In my own paper on the drift of Keeling 

 Atoll and of the south coast of Java no reference is made to them; 

 and the same remark applies to the writings of Treub, Penzig, and 

 Ernst on the new Krakatau vegetation, and to Moseley's account of 

 the drift observed by the Challenger Expedition off the coast of New 

 Guinea, as given by Hemsley (Ibid., IV., 285). It is possible that 

 such fruits may have been at times regarded in the same light as 

 the empty mango stones so frequent in tropical beach-drift, but this 

 seems hardly likely. 



The divergence in opinion relating to the claim of Cassia fistula to 

 be ranked as an indigenous American tree is illustrated by Hemsley. 

 Whilst in one place he includes it amongst those plants certainly or 

 probably dispersed by currents, in another place, when dealing with 

 Jamaican beach-drift, he writes that it doubtless owes its present 

 wide area to man rather than to any other agency (Chall. Bot., I., 43 ; 

 IV., 301). It is odd that its pods are a feature of tropical beach-drift 



