( 16 ) 
in July fine patch.es of fresh water Algae in the creeks north of Watering 
Cove. 
(3) .—The scarcity of Melastomaceae (2 sp.?), Tiliaceae, Gesneracese, 
Solanaceae (lsp)., Urticaceae (lsp,), Ternstroemiaceae (1 sp.) 3 Bego- 
niacese, (1 sp.) Piperaeese, Aroideae and Aspidieae. 
(4) “The extreme scarcity of annual plants and of so called 
weeds beyond Port Blair is undoubtedly a most remarkable feature 
in the Andamanese flora. 
All the weeds enumerated in my list are evidently of late introduction, 
and, therefore, cannot be treated as elements of the flora. Wherever clearings 
take place the soil remains barren, and only Acanthacese, shrubs and other 
woody plants come up, with which Yitis, Leea, &c., are associated during the 
rains. 
Scarcely any indigenous weeds are seen on such spots, but numerous 
introduced weeds appear in localities which are protected, or in the valleys ; 
amongst these Scoparia dulcis , Ageratum conyzoides, Vernonia cinerea , and 
several Cyperacece occupy the first place. 
The great number of introduced plants already appearing almost indige¬ 
nous, in spite of the short time of our occupation, will be easily understood 
when we recollect that extensive sowings of grasses, &c., have been made all 
around the stations within the last few years, so that the originally barren 
yellowish ground is covered with an agreeable verdure during the rains. 
When drawing our attention from the deficiencies, and directing it to those forms 
quite peculiar to the islands, and to those families best represented there, we 
perceive that, with regard to the latter, the Andamanese flora has but little 
peculiarity in comparison with the Burmese and Malayan floras. 
As a few examples of apparently peculiar forms in the Andamans, but 
not yet known from Burmah, I can note Freycinetia , Mimusops Indica , Anaxa- 
gorea Zeylanica , Hy dnophy turn formic arum , and a number of the species, now 
described by me as new. But even these forms cannot certainly be pronounced 
peculiar, as I feel sure that many of them will be collected in Burmah at some 
future time; moreover, the Burmans in the Andamans know most of them 
by name. 
22. It is important to know the flora of the Andaman Islands in all its 
Importance to distinguish introduced completeness as soon as possible, as the increasing 
plants from the indigenous ones. clearings and subsequent cultivations have already 
caused a number of introduced plants to become as if they were indigenous, so 
that it is only possible to declare a species really introduced after having explored 
the surrounding regions. 
All our inquiries into the laws of distribution of plants depend chiefly 
upon the knowledge of unmixed floras, and the Andamanese vegetation is 
probably the only unmixed one existing in tropical Asia. 
I may remark here that Mr. Homfray himself has informed me that 
he has made many sowings of different species, as Ganna, Mirabilis, &c., 
in the interior of the jungles. 
23. A considerable number of plants appear on the Andamans 
Centres of species of plants. concentrated on one or more spots, where they 
occur in great abundance, diminishing in number 
of individuals, or disappearing altogether as we remove from their centres. 
Such spots may be called botanical centres of species. 
A species may, therefore, occur in great quantity over a certain space, 
but be found nowhere else. In other instances, a species may occur at a 
spot in great quantity and disappear to make place for another prevailing 
type, but it may make its appearance again under similar circumstances at 
some other spot. 
