102 A NATURALIST ON DESERT ISLANDS. 



unconsciously distributed the seeds of land plants, which 

 had become attached to their plumage, or in the case of 

 waterfowl to their feet, or which had passed through 

 their alimentary system undigested. Various species of 

 duck * and waterfowl habitually visit Swan Islana during 

 the migratory season at the present day, so that there is 

 no cause to work upon our imagination in regard to them. 



Pigeons, too, not to mention other seed-eating birds, 

 form a conspicuous feature of the bird population 

 of the island ; and, as is well known, pigeons have probablj^ 

 played as great a part in the dispersal of island floras as 

 any birds which we know of. We msij refer here to the 

 very curious fact that the little West Indian ground-dove 

 (Chamcepelia) is not found on Swan Island, for as far as 

 our personal experience goes, this bird is found, without 

 exception, iu all the ether islands, big or small, in the 

 Caribbean basin. Still, although it is not present now, 

 it may well have been blown here by adverse winds in 

 the early days of the floral colonization of the island, 

 and have played its part before a uniform and thick 

 growth of forest trees had rendered its existence on the 

 island an impossibility. 



And in any case it is just these little accidents or 

 anomalies of distribution, which we may feel certain 

 exercised an appreciable effect on the vegetation, and the 

 absence or presence of certain species of plants. It is, 

 indeed, no exaggeration to say that the mere " accidental " 

 presence, or the mere accidental " absence, of these small 

 seed-eating, ground-feeding doves, may have been answer- 

 able for shaping the entire vegetative aspect of the woods 

 of Swan Island. That is to say, it is quite conceivable. 

 If it were not so there would be no interest in trying to 

 unravel the threads of the fascinating puzzle presented 

 by any and every insular flora. 



So the seeds, brought by all these land-birds, by many 

 a fortuitous chance, germinated, grew, reproduced them- 

 selves, struggled gamely against adverse circumstances, 



*The islanders once shot 41 canvas-backs in a week. 



