260 
spontaneously and appearing likely as time goes on to increase perceptibly 
the numbers of the non-indigenous flora. The greater number of these 
must have certainly been introduced in the 1789-92 period, and many of 
them are such as at first sight suggest for themselves the possibility of 
survival. 
Perhaps, however, it ought not to surprise us greatly that species 
which readily appear spontaneously elsewhere and which are appearing 
spontaneously in the Andamans now, should, if they were previously in¬ 
troduced, have perished between 1792 and 1858. Most of them are plants 
that, when they do escape from cultivation and appear spontaneously, 
affect such situations as waste places, rubbish heaps, road-sides, hedge¬ 
rows and margins of clearings,—situations that have at least this in 
common, that they afford their denizens abundance of air and light. 
Many of them too are herbaceous, or at most fruticose, and the native 
jungle as it reinvades the abandoned clearings overshadows them and 
either chokes them completely, or by merely preventing them from 
flowering, makes their fate only a matter of time. Even trees that seem 
quite naturalised in clearings must soon succumb to the weight of creepers 
that rapidly overload them in a forest. 
If, however, the survival of even a small proportion of the cultivated 
species abandoned in 1792 will suffice to explain the higher rate of na¬ 
turalisation during Period I, deducible from the figures in Table III 
(Carica Papaya and Cocos nucifera are excellent examples of such sur¬ 
vival), there is no similar explanation possible for the higher rate of weed- 
introduction during the same period. A considerable number must have 
been already introduced by 1792, and, though many doubtless yielded to 
the influences adverse for naturalised cultivated species, weeds are often 
proverbially tenacious of life and a good few, as the notes against them 
show, in place of avoiding the jungle are actually penetrating into it. 
Taken altogether we find that the rate of introduction during the first 
period was 2^ times as high as it has been during the second, and the 
most probable explanation of this higher early rate of weed introduction 
appears to be that in the dirty grain of an Indian bazaar seeds of most 
of the commoner Indian weeds are certain to be present. This being 
the case so many weeds become introduced with the very earliest sowings 
of any grain that the subsequent rate of introduction of species can be but 
small. And it is highly probable that for the same reason the rate of weed- 
introduction becomes year by year diminished. Unfortunately it has not 
occurred to any one to make observations on these weeds during the 
interval 1858-66 or 1866-90. And without repeated observations after 
short intervals of time, especially towards the commencement of a 
settlement, it is impossible to test the adequacy of this explanation. 
50 
