44 Proceedings of the Eoyal Irish Academy. 



various j)omts iu the Atlantic by the Ignited States Hydvogiaphic Office, by 

 the Prince of Monaco, and by many other investigators. An obvious and 

 unavoidable source of error iu s'uch experiments lies in the uncertainty as to 

 the lenglli of time whicli may elapse between the straiuliiig and tlie Kudiiig of 

 a test bottle or lloat on the European shores. This source of error Dr. Guppy 

 largely eliminates by selecting in the cases of recovered Hoats or bottles those 

 intervals between throwing ovei'board and recovery which are the shorter by 

 20 or 25 per cent. An average of these sliorter intervals he righdy considers 

 as most closely approaching to the real duration of the passage, and so treatnig 

 the considerable body of available material, he arrives at an average rate of 9-^ 

 miles per day for the 4000 miles drift from the West Indies to the shores of 

 Europe, or about fourteen months for the wliole transit. The shortest passage 

 recorded is one of about eleven months for the 4100 miles from Hispaniola 

 to the Irish coast. In all cases the rate varies greatly in different sections of 

 the route travelled, and, as Dr. Guppy points out, the system of oceanic 

 currents is such as to make it possible for a West African Guinea Coast seed 

 to reach the European shores by crossing the South Atlantic to Northern 

 Brazil, and passing liience by tlie Carribean Sea and Gulf of Mexico into the 

 Gulf Stream. Tliis voyage of upwards of 10,000 miles would be accomplished 

 in about two yeare ; and as Enlada scandcns occurs in West Africa, it is 

 possible, if by no means probable, that some of its many higlily buoyant 

 beans found stranded on the Irish coast may have once grown on the banks 

 of the Niger or the Congo. 



In most of the earlier records of the discover)' of exotic drift seeds on the 

 Scottish coast, for iustance, iu Mackenzie's account, already cited here (1675), 

 in Sibbald's "Scotia Ulustrata" (1G84),' iu Wallace's " Description of the 

 Isles of Orkney " (169."^), and in Martin's well-known " Description of the 

 Western Islands," the seeds are sjioken of as Molucco Beans, and this name, 

 however originated, gave rise to tlie theory that the beans had travelled by 

 sea fiom the famous Spice Islands of the eastern tropics. Mackenzie in his 

 1675 paper discusses in these words the probable path travelled by the 

 beans : — 



" Now, considering the sctuation [sic] of these isles (Hebrides) witli respect 

 to any place where Molucco Beans grow, let the observers of Tydes consider 

 what reciprocations must be imagined to adjust the Eastern and Western 



' Pars secuncU, p. 55 : — In littore Maris DeitcaiedoHxi tb in Orcadibiis cum Alga 

 Marina inreniutiltir Phnscoli Molucatii <t- iS'tijc Indica tx qua Pyxides pro Piihere aUr- 

 nnatoris pnrani. In this passage it will be seen that Kntada is called an Indian Nut, 

 while the name Molucco Beans is applied to other sea- borne seeds, probably to those of 

 Guilandina. 



