46 THE VOYAGE OF H.M.S. CHALLENGER. 



amara, Xirnenia americana, Eugenia, Psychotria, Premnaf Cassytha Jjliformis, 

 Laurinese various (including Litsect), Myristica, Phyllanthus, Ficns, Gnetum, Clinogyne 

 grandis, Areca, Kentia, and Orania. 



This is a very small list, and is merely offered as an example of what is done by birds. 

 As Dr Beccari, Mr Moseley, and others have pointed out, the fruit-pigeons are able to 

 swallow much larger fruits than would seem possible ; and the cassowaries of New 

 Guinea, on the authority of the former, swallow the fruits of Orania aruensis, which are 

 two inches and a half in diameter. 



EXAMPLE OF AN ISLAND WHICH HAS BEEN LARGELY FURNISHED 

 WITH PLANTS BY OCEANIC CURRENTS AND BIRDS. 



In his notes on the vegetation of the Admiralty Islands (reproduced in Part III., pp. 

 227-231), Mr Moseley gives some particulars of the means by which newly raised coral 

 islands become stocked with plants, and the kinds of trees which successively follow each 

 other. Dr Guppy, too (see Part III., p. 309), and Dr Beccari (loc. tit., p. 312), contribute 

 some interesting facts in relation to the process ; and with the evidence we have collected 

 from other sources before us, there is no difficulty in drawing a complete picture of the 

 various phases in the production of an insular flora, such as that of the Arrou or Admiralty 

 Islands, for example. The lists given above might be extended considerably on the 

 assumption that if such and such plants owe their present distribution to these agencies, 

 numerous other plants bearing similar seeds or fruits were dispersed in the same way ; but 

 there is no need for speculation, as the evidence is sufficient to account for the vegetation 

 of most of the islands, except those placed in our first category (p. 6), and characterised 

 by having a large endemic element including generic types. From the positions of these 

 islands, it is improbable that birds have effected much, if anything, in stocking them with 

 plants ; and the littoral element is almost entirely wanting, in consequence of the nature 

 of the shores being such as to render it impossible for plants to establish themselves 

 thereon. 



Taking a very small selection of flowering plants, whose seeds are transported by 

 oceanic currents and birds, we may trace the gradual invasion of an island by herbs, 

 shrubs, and trees. Actual evidence of the germination of drifted grass seeds is wanting, 

 and most of the drift-seeds that certainly retain their vitality, as explained before, are 

 either exalbuminous or have oily albumen ; but Darwin's experiments proved that many 

 seeds having farinaceous albumen — those of the oat, for example, will bear long immersion 

 in sea-water without injury to their germinative power. Hence we may assume that the 

 seeds of many almost ubiquitous sand-binding grasses may be reckoned among those which 

 iire cast ashore in a vital condition ; and we may also assume that these grasses are 

 among the very first flowering plants to obtain a footing. Other herbaceous plants met 



