FOREIGN DRIFT OF THE TURKS ISLANDS 163 



and he also identified it with others he had often seen in collections 

 of rare fruits. Though, as he says, authors were silent as to its 

 source, and he himself had " never seen it grow," he rightly sur- 

 mised that the sea had brought it to the Orkneys from the West 

 Indies. The peculiar form of the fruit often tempted the old authors 

 to make a drawing of it. Though the figures are rude, they are 

 accompanied by good descriptions. 



J. Petiver, F.R.S., a contemporary of Sloane, described and 

 figured the fruit in his Gazophylacium Naturce, a remarkable work 

 containing 1000 illustrations of objects of natural history, and pub- 

 lished with varying form and title from 1695 to 1764. Under the 

 name of Faba Orcadensis, he describes it as " nigra, polita, tetra- 

 sulcata, hilo magno," and, like Sloane, he refers to Clusius in this 

 connection. Like Sloane, also, he alludes to its being figured in 

 Wallace's account of the Orkney Isles, though in this case it is the 

 son's enlarged book that is concerned. " My ingenious friend, 

 Mr. James Wallace, Physician " (thus Petiver writes), " hath figured 

 this in his Description of the Orckney Isles, p. 14, from whose shoars 

 Mr. Will. Clerk brought it me. Father Kamel hath also sent me 

 the same from the Philippine Isles." [Petiver's description of the 

 fruit is given in a small octavo volume published in 1702, p. 54; 

 whilst the figure it concerns is to be found in a large folio volume 

 (table 34, fig. 10) issued in 1764, the contents of the first fifty tables 

 being described in the smaller volume. It is ill-figured, but well 

 described.] 



It is evidently to this fruit that Pennant alludes in his account of 

 his Voyage to the Hebrides in 1772, which has been already quoted 

 (see p. 32). After naming four kinds of " Molucca Beans " thrown 

 up on this group, he says that " the fifth is a seed called by Bauhin 

 'fructus exot: orbicularis sulcis nervisque quatuor,' whose place is 

 unknown." He appears to have had access to Sloane's account of 

 the West Indian drift seeds on the Orkney Islands ; but there is no 

 reference to it. C. Bauhin's Pinax Theatri Botanici (1623, p. 405) is 

 evidently the work quoted by him ; but Bauhin, as previously stated, 

 had merely quoted the earlier work of Clusius. 



This discussion may be concluded with a few remarks on the 

 nature and cause of the buoyancy of these 4 i composite " seeds, as 

 one might term them. Of the three specimens obtained from the 

 beach-drift of Jamaica, the Turks Islands, and the Shetlands, all 

 floated in sea-water, but two, including the Shetland seed, sank in 

 fresh-water. In other words, all were specifically lighter than sea- 

 water, but two were heavier than fresh-water. This behaviour, 

 interpreted in the light of a somewhat extended acquaintance with 

 the subject of the flotation of fruits and seeds where the average 

 specific weight happens to be near that of sea-water, indicates that 

 a large proportion of these " composite " seeds produced by the 

 plant would not possess buoyancy in any sense. As in the case of 

 convolvulaceous seeds generally, the floating power is to be ascribed 

 entirely to the cavities produced by the shrinking of the albumen 

 and embryo during the hardening stage, the separate parts having 

 no independent floating capacity. 



