258 ^' Prain — The non-indigenous species of the Andaman Flora. [No. 3, 



name of Port Gornwallis by Lieut. Blair* in 1789, in obedience to orders 

 issued in September of that year. In November 1792 orders were issued 

 for the removal of the Settlement to another and more spacious harbour 

 in North Andaman ; to this new settlement the original name Port 

 Gornwallis was again applied. It is nowhere distinctly stated, though, 

 considering the transfer of name from the old settlement to the new, it 

 is highly probable, that old Port Gornwallis was entirely abandoned in 

 1792. We know, however, that in 1796 orders were issued for the re- 

 moval of the whole establishment to Penang. The doubtful point, so 

 far as our present enquiry is concerned, is the length of time prior to 

 the establishment of the present Settlement that its site was exposed to 

 influences favourable for the active introduction of non-indigenous 

 species. But we know that altogether these influences only existed for 

 six seasons and could only have been active during three seasons ; probably 

 they only existed at all during these three seasons. The present Settle- 

 ment was commenced in March 1858 ; Mr. Kurz visited it during April- 

 July 1866 ; to the eight seasons (1858-66) that had passed between the 

 foundation of the Settlement and the date of that visit we must therefore 

 add three more seasons (1789-92) in order to make up the whole period 

 during which the non-indigenous species recorded by Mr. Kurz were 

 being introduced. Even if the original site was not wholly abandoned 

 in 1792 the subsequent seasons (1792-96) may be neglected without 

 producing any appreciable error. Assuming, therefore, that a period of 

 eleven seasons has been responsible for the naturalisation and introduc- 

 tion of the species in the two lists for 1866 we are able to calculate the 

 rates of these processes and to compare them with the rates between 

 1866 and 1890. These are shewn in the following table :— 



Table III. — Bate of Introductio^i of Non-indigenous Species. 



Non-indigenous species na- 

 turalised. 



During Period I. 



Prior to 1866 (1789-92 + 



1858-66) =11 seasons. 



During Period II. 



Bet. 1866 & 1890, (1866-90) 



= 24 seasons. 





No._ 

 of species. 



Rate 

 per annum. 



No. 



of species. 



Rate 

 per annum. 



Cultivated plants introduced 



during Period I ... 

 Cultivated plants introduced 



during Period II 

 Weeds of cultivation 



15 



61 



1-36 

 5-54 



14 



9 



56 



0-58 



0-37 

 233 



Totals ... 



76 



6-90 



79 



3-28 



* The name of the 1789 Settlement having been transferred to the one founded 

 in 1792, the present Settlement, which occupies the site of the 1789 one and vi^hich 

 dates from March 1858, has been named Port Blair in honour of the original 

 founder. The name Fort Cormoallis is still used to designate the site of the Settle- 

 ment in North Andaman that existed from 1792 to 1796. 



