82 A NATURALIST IN THE PACIFIC CHAP. 



the place in the Old World which Mucuna urens takes in America, 

 and it is curious that they meet in Polynesia, being sometimes 

 associated as in Hawaii. In the chapter on my observations in 

 Ecuador and in Panama it is remarked that Mucuna seeds are 

 frequent constituents of river, sea, and stranded drift. I, therefore, 

 have enjoyed the opportunity of observing the behaviour of the 

 seeds of this genus in a variety of localities, namely, in the Keeling 

 Islands, in West Java, in Fiji, Hawaii, and tropical America ; and 

 this may be pleaded as an excuse for entering into so much detail 

 respecting them. 



The large seeds of Strongylodon lucidum (S. ruber), a Leguminous 

 liane that ranks with the species of Mucuna amongst the huge 

 climbers of the forest of the Pacific islands, behaved in a similar 

 way in my flotation experiments in sea-water. Though, as shown 

 in Note 3, these seeds can float for a year and retain their 

 germinating power, some of them brought their buoyant capacity 

 prematurely to an end by an abortive attempt at germination. 

 These black rounded seeds form a common object amongst the 

 river seed-drift stranded on some of the Fijian beaches in the 

 vicinity of estuaries. They are so hard and durable that they are 

 mounted in brooches in Honolulu. Yet these pebble-like seeds will 

 sometimes begin to swell in a few days in sea-water. Out of five 

 seeds placed in sea-water in England under warm conditions (the 

 water temperature for the first few weeks ranging between 75 and 

 90 F.), one swelled and sank within ten days, another did so after 

 two months, whilst the other three were afloat after twelve months,, 

 and one of them subsequently germinated. There is some 

 disagreement amongst botanists as to the limits of the specific 

 characters of the plants of this genus (see Note 39) ; but the 

 plan seemingly most in accord with the fundamental principles 

 regulating plant-distribution in this region of the Pacific is to* 

 regard the forms found in Hawaii, Tahiti, and Fiji, as referable to 

 one species. In addition to the Polynesian forms there are only 

 two or three species, found in the Philippines, Madagascar, and 

 Ceylon, and it is with the species from the last-named locality that 

 the Polynesian species is by some identified. 



The seeds of several other Leguminous climbers would probably 

 act in a similar way, for instance, those of Entada scandens ; but 

 the seeds of this plant experimented on by me were too few to- 

 enable an opinion to be formed. Of four seeds of Dioclea violacea 

 from Fiji that were subjected to the same experiment as those of 

 Strongylodon lucidum, all floated in sea-water after a year, with 



