98 A NATURALIST ON DESERT ISLANDS. 



— ^how, exactly how, did it arrive ? And having once 

 arrived, how did it establish itself ? 



We shall hope to prove later that Swan Island (as it is 

 to-day) has never had any dry-land communications 

 with the mainland, and might in fact be very well called 

 a pseudo -oceanic island.* Therefore everything in the 

 nature of its flora, not accidentally introduced by man, 

 obtained originally a footing through the agency of birds, 

 sea-currents, or winds. I put them in their order of 

 importance, as they seem to me to have affected Swan 

 Island. These means of the dispersal of plant-life are 

 now too well known to dwell upon. But it would appear, 

 that it is not all just quite so easy as we have been 

 accustomed in this light to regard it. 



One has thought, for instance, of the seeds of plants 

 or trees floating for indefinite times, until chance washed 

 them up upon the shores of islands such as these, and 

 then — " well, of course, there you are, you know — the 

 thing grows." However, according to the recent state- 

 ments of Mr. Wood- Jones in his " Corals and Atolls," 

 this seems far from being the case. In the great majority 

 of instances, at the moment when success appears 

 to be within the very grasp of the enterprising seed, 

 something seems to be wanting ; the process breaks do^^^ll. 

 Here is what Mr. Wood- Jones says. He is writing of the 

 Cocos Keeling atoll : " Concerning those plants the seeds 

 of which are hard £^nd fitted for a sea journey, some very 

 interesting points are to be noted. On the island beaches, 

 are many kinds of seeds which may be picked up any day 

 — there are perhaps half-a-dozen kinds, of which one 

 specimen could be found almost with certainty in a walk 

 along a hundred j/ards of beach. Now, these seeds will 

 grow with great readiness when picked up and planted 

 in the earth , but as their leaves become recognisable, 



* At six miles clue south of the islands the soundings show a depth of 

 1,053 fathoms Fourteen miles due north 3,010 fathoms are recorded, 

 while at thirty-seven miles in a south-westerly direction 2,350 fathoms 

 are reached, and at fifty miles in an easterly direction they show 3,206 

 fathoms. — Admiralty Chart, 1877. 



