FOREIGN DRIFT OF THE TURKS ISLANDS 153 



less of the fruit's length. Yet most of the seeds are too large to fall 

 out of the pod at first; but the waves would soon complete the 

 process of destruction, and the floating pod, with long rents in its 

 sides, would probably not survive more than a month or two's 

 buffeting in the currents. Only the pods of C. -fistula would be able 

 to withstand the " wear-and-tear " involved in the passage across 

 the Atlantic to the shores of Europe. It is, therefore, at first sight 

 not surprising that they alone have been found stranded on European 

 beaches. 



But before dealing with this matter, I will refer to the condition of 

 the seeds in the fruits thrown up on the beaches of the Turks Islands, 

 which represent the end of an early stage in the transatlantic 

 voyage. Most of the seeds of these two species of Cassia are im- 

 permeable to water, and they would withstand for a long time the 

 effects of the penetration of sea- water into the floating fruit, which 

 takes place sooner or later when the long pods, as generally happens, 

 break in two. Those that are permeable would quickly swell up and 

 lose their germinative capacities; whilst in time a number of the 

 impermeable seeds would be also unable to retain their impervious 

 character under the warm, moist conditions of the drift in tropical 

 seas, and they, too, would swell up and become useless for propagat- 

 ing purposes. But a good proportion of the seeds would be able for 

 long periods to resist the penetration of sea- water, and transported 

 in the floating fragments of the pod they would retain their sound 

 state when stranded on some distant coast. Of the seeds found in 

 the fragments of the pods of C. fistula and C. grandis on the beaches 

 of the Turks Islands, between 20 and 40 per cent, were generally 

 hard, entire, and quite sound on section; the rest had lost their 

 germinative powers, having swelled up after the sea-water had 

 penetrated the drifting fruit. 



The fragments of the pods of these two trees that are stranded on 

 the Turks Islands could at the most have only drifted a few hundred 

 miles, and seeing that more than half of their seeds have been killed 

 by the penetration of sea-water, it seems unlikely that many sound 

 seeds would be found in the pods of Cassia fistula that have been 

 picked up on European beaches. I am assuming here that such 

 fruits hail from the New World, which at first appears reasonable, 

 since they are associated in the European beach-drift with seeds of 

 Entada, Guilandina, Mucuna, etc., that undoubtedly come from the 

 American side of the Atlantic. 



It would seem, however, that the records of the stranding of the 

 fruits of C. fistula on the European side are not numerous. Accord- 

 ing to Sernander (p. 117) they were found on the Norwegian coasts 

 by Strom and Gunnerus, who flourished about the middle of the 

 eighteenth century. Lindman in recent years has confirmed the 

 identification of the species (Sernander, Ibid.). In this matter 

 Hemsley (Chall. Bot., IV., 277) quotes Tonning, a pupil of Linnaeus, 

 through whom the observations of Strom and Gunnerus, as Sernander 

 points out (p. 116), are usually known in the scientific world. 

 Nothing, however, is said by Sernander as to the condition of the 

 pods and of the seeds when gathered on the Scandinavian beaches. 



