Fortunate Islands 



tissue, the result of a water life, has been utilised and 

 developed to serve a totally different purpose, that of 

 floating and so voyaging to distant islands. 



There are two groups of these navigators. One set 

 consists of the mangroves and their attendant satellites. 

 These are specially adapted to colonise muddy estuaries 

 (see p-3 2 5). The rest are the ordinary coral strand plants. 



Dr. Guppy found by actual experiments that the 

 seeds of 95 per cent, of the eighty navigators were able 

 to float ; 75 per cent, of them were kept in the water for 

 two months, and showed no sign of losing buoyancy. 

 For comparison he collected a hundred seeds of inland 

 plants in one of these South Sea islands and found that 

 75 per cent, of them sank immediately. 



The history of the colonisation of the Pacific Islands 

 is still obscure, but the general course of it has been 

 traced from Indo-Malaya to the eastward. As one 

 proceeds east, the number of these navigator plants 

 becomes gradually less. Tahiti, for instance, only pos- 

 sesses fifty-five out of the eighty species recognised as 

 characteristic, and it is only cosmopolitan species that 

 have managed to reach the American coast-line. 



But the unfortunate point is that the ocean currents 

 in the Pacific do not flow from west to east ; indeed, 

 the north and south equatorial currents are exactly 

 opposite to the apparent direction in which these plants 

 have travelled. 



There are currents by which the navigators could travel 

 without difficulty from the Malay peninsula as far as 

 the Philippine Islands and even to New Caledonia, but 

 from this point to Tahiti they have managed to travel 

 against the regular drift, which is from east to west.* 



* Dr. Guppy suggests that during the north-west monsoon, that is, from 

 January to March, some might have reached the Solomon Islands and others 

 by the Caroline, Marshall, and Ellice groups. There is also the counter 

 current (west to east), which might have been utilised by some of them. 



280 



