1891.] T>. Prain — Vegetation of the Cocos Group. lo9 



As regards distribution : — 70 are cosmopolitan in the tropics, 10 

 more are present in tlie tropics of both hemispheres, but are scarcely 

 cosmopolitan; 49 are widely distributed in the eastern hemisphere; 

 41 are confined to Asia and Australasia ; and 188 are confined to South- 

 eastern Asia. 



As regards more local distribution : 252 species extend to India, 

 or Ceylon, or both ; 153 species extend to Australia ; 140 species to 

 China. 



The islands lie so to speak intermediate between the Indo-Chinese 

 and Malayan phytogeographic districts and the following is the oc- 

 currence of species within these : — confined, so far as is yet known, to 

 the Coco Group, 13; occurring in the Andamans, 324 (90°/^); occur- 

 ring in Malaya, 275{7Q°/ J ; in Tenasserim, 259 (72%) ; in Indo-China, 

 256 (71%) • We conclude therefore that the group forms phytogeogra- 

 phically part of the Andamans and that in its flora a Malayan influence 

 predominates slightly over the Indo-Chinese. 



Examined with a view to ascertaining more precisely the probable 

 origin of the flora we find that of species which may possibly have 

 been introduced (not thereby necessarily implying that they are not 

 indigenous but simply pointing out that it is not essential, in order to 

 account for their presence, to postulate a connection of the islands with 

 neighbouring land) the list contains 288, as opposed to 70 that seem to 

 require the conception some former land-connection in order to explain 

 their occurrence. The proportion of Migrant (possibly introduced) species 

 to Remanent (certainly indigenous) species is therefore 4 to 1. The 

 remanent species indicate that the most recent former land-connection 

 may have been with Indo-China. 



Of the introduced species 33 are " civilized" plants, cultivated plants 

 or weeds, introduced voluntarily or involuntarily by man ; 94 have been 

 perhaps introduced by birds (assisted perhaps slightly by frugivorous 

 bats) ; 60 have been introduced by winds; 101 by the sea. 



Of the sea-introduced species 21 are marine plants, 80 are littoral 

 species ; they appear to have come wholly from Malayan seas. The 

 wind-introduced species indicate that it is the north-east (not the south- 

 west) monsoon which is the more important factor. This might be 

 expected since the latter blows over a wide expanse of ocean to these 

 islands, while the former, though not so strong, blows steadily for some 

 months each year from the direction of the nearest land. The bird-in- 

 troduced species are of two kinds : — Those attached externally to the 

 bodies of birds and those carried in the crops of birds. Of the first kind 

 there are two sub-groups : a. those attached immediately to their bodies 

 by reason of the fruits being viscous or being provided with barbs or 



