

238 



GEOGEAPHICAL DISTEIBUTTOX 



sufficient to justify 

 district; an 



us in looking on 



The degree of isolation indicated by the endemic percentage seems in this case quite 



Assam as a priori a distinct phytogeographical 

 d as in this case again the amount of connection with Burma is decreased 

 instead of increased when approximately natural units are employed in computing it, it 

 becomes necessary to look upon the two as separate. 



In the Andaman islands only one species {G. oblongum) has been found. As this 



occurs in 



precisel 



T7 



J 



genus 



is 



concerned, has 



the same form in Tenasserim, the Andaman group, so far as this 



to be annexed to that district. In the Martaban-Tenasserim 



district itself — the district of the Malay Isthmus — four other forms have been found. 

 These are G, strobilinum var. viridis, which is not specifically, and is perhaps hardly 





varietally, different from the Arracan G, strobilinum var. acaulis ; G, crinitum var. 



typica. 



which extends to Burma and Assam on the one hand and to the Malay peninsula on the 

 other; G. Scortechinii var.? Helferi, el plant that is apparently a variety of a Peninsular 



species 



> 



and G. 



rugosum, a species that also appears in Java. The subjoined table gives 



the distribution of these Tenasserim-Andaman species: 



Table VIII. — Table of distribution for Tenasserim-Andamans. 



Name of Species 



G. oblongum 



• ♦• 



• • • 



G-. rugosuia 



• • • 



G. strobilinum (1 var.) ... 

 G. crinitum (1 Tar.) 



Totals of artificial speoies 



Percentages of ditto 



ft • ■ 



G. Scortecbinii (1 var.) ... 



%•• 



• •• 





• • • 





Totals from probable natural species 



Percentages from ditto 



Endemic. 



1 



3 



• • • 





55°/ 



1 



1 



12 



• • • 



To Burma. 



• • • 



• •• 



40°/ 



t • • 



• 9 • 



1 



2 



1 



I 



• • • 



J 



1 



5 



157, 



I 



4, 



1 



4 



307, 





To Malay Peninsula 

 and Archipelago. 



■ 



• • • 



i 



• • • 



i 



li 



457, 



i 



• • • 



1 



4* 



5 

 T2 



507, 



In 



this case the degree of isolation indicated by the endemic percentage is somewhat 



decreased when approximately natural units are used in computing it. This prevents our 

 feeling justified in considering the district phytogeographically distinct; as the same 

 process increases both the Burmese and the Malayan percentages, causing the latter to 



exceed the endemic percentage, the annexation of the district to Malaya is strongly 

 suggested. 



