302 Christmas Island, 



by single individuals, wHcli were picked up in a dying condition ; 

 this was the case with the specimens of Chalcococcyx hasalis and of 

 Sirundo gutturalis. Since T left the island several individuals 

 of a black and white fruit-pigeon {Myristicivorus hicolor) have been 

 observed on the island, and I heard reports that similar cases had 

 occurred previously ; but it seems unlikely that this species could 

 become a permanent inhabitant, for it would probably come into 

 direct competition with the native fruit - pigeon, which itself 

 sometimes dies in large numbers for want of sufficient food and 

 water. Several other birds, of which 1 did not obtain specimens, 

 have been observed. Mr. Andrew Ross told me he had shot 

 a small duck and that a fishing hawk had been seen on the coast. 

 I myself saw a number of white-headed swifts which remained 

 for some days. Whatever the reason may be, it is certain that for 

 an extremely long period of time no bird has become a permanent 

 denizen of the island, for all the land birds which breed there are 

 peculiar species, whose ancestors must have arrived long ago. It 

 should be noted, moreover, that according to Mr. Lister, who has 

 ably discussed the geographical relations of the Christmas Island 

 birds [5], they are more nearly related to Austro-Malayan than 

 to Javanese types. This circumstance may be accounted for by 

 supposing that when their ancestors reached the island diflPerent 

 meteorological conditions prevailed, or that they may owe their 

 introduction to some other cause, e.g. drifting on rafts of floating 

 trees such as not uncommonly occur in these seas. 



Of the insects the dragon-flies, which arrive in swarms, usually 

 disappear in a few days, most likely because of the absence of 

 standing water. The butterflies and moths were generally much 

 battered during their transit, and it can only rarely happen that 

 the conditions necessary for their establishment as permanent 

 inhabitants are fulfilled. Of the other less conspicuous insects it 

 is impossible to speak, because I was unable to distinguish the new 

 arrivals from the natives, but no doubt many species must from 

 time to time be blown across from Java during these gales. 



Of the plants, according to Mr. Ridley [8], very few are 

 introduced by the wind, the most important being the various 

 Cryptogams, of which the small spores are easily blown long 

 distances ; orchids, of which the seeds are very small ; Hoy a and 

 Blumea, the seeds of which are plumed ; and to these perhaps may 

 be added Berria and Bipterocarpus, the winged fruits of which 

 are sometimes carried high into the air and may be blown long 

 distances. 



The ocean current which passes the island is the equatorial drift, 

 which comes down from the Timor Sea and receives tributaries 

 through the Straits between the islands of the Archipelago (Bali, 

 Lombok, etc.). It is to the transport of rafts of trees by this 

 current that the rats, the fruit-bat, and possibly some of the land 

 birds, very probably owe their introduction to the island, and this 

 circumstance would account for the similarity of many of them to 



