No. 31.— 1385.] 



CEYLON FLORA. 



157 



America. This is also the only member* of the large 

 order of Cactacece, which grows naturally outside of the 

 American continent. A few other examples of this connec- 

 tion with the West might be given, f though they are very few 

 compared with the large number which Asia has given to 

 Mauritius. But they equally point to a means of communi- 

 cation, which, it appears almost certain, once permitted 

 the passage of organisms across the Indian Ocean. J The 

 hypothetical continent of " Lemuria" invented to account 

 for the distribution of that curious group the Lemurs, of 

 which our Loris is a member, has been found unnecessary 

 in the light of paleeontological discoveries, but the existence 

 of the very extensive shoals, coral reefs, and islands which 

 are known under the names of the Carcados, the Chagos, 

 and the Maldives, show the former existence of a series 

 of very large islands in the deep ocean, and bridging the 

 distance at intervals. 



The Maldives possess a special interest for us. The sunken 

 land upon which the " 12,000 isles" have been built up by 

 the coral-makers must at the lowest computation have 

 been 500 miles long and 100 broad ; another Sumatra 

 must then have approached close to our shores. Now, the 

 nearest atoll is 350 miles from Cape Comorin, and 400 from 

 Ceylon, and the wild vegetation consists merely of a few 

 sea-shore plants brought by the waves, and some weeds of 

 cultivation. But in the past which has made the present, 



* A second species of Rhipsalis has lately been found in Madagascar. 



| There are also similar cases in the Peninsula in the genera Nare- 

 gamia, Calpumia, Hardwickia, Droguetia, &c. 



\ Several botanists have remarked that the main direction of the 

 migrations of plants is from east to west, and it has been suggested that 

 this is connected with the earth's rotation. We are also led from many- 

 considerations to the inference that the world has been originally 

 stocked with plants from the north. Migration generally, then, when 

 unchecked by insurmountable barriers may take an average course of 

 from north-east to south-west. This consideration may tend to explain 

 the fact that the great accumulations of endemic species are so often 

 found crowded together in the south-west extremities of continental 

 areas. The neighbourhood of Cape Town in South Africa and West 

 Australia are striking examples ; the Xndo-Ceylonese flora under ex- 

 amination may perhaps afford another less marked one, and similar 

 phenomena in a smaller scale are to be seen in Europe and its Islands, 



B 2 



