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Java was not established until 1817. About the end of the 
eighteenth and beginning of the nineteenth century, botanic 
gardens were established in many of the more advanced tro- 
pical colonies, such as India, Java, Ceylon, Jamaica, Demarara, 
an others. 
Now the object with which these gardens were opened was 
in general the same: to introduce into the country and accli- 
matise there the usefel plants of other countries, and we must 
endeavour to discover with what success they achieved this 
aim; in general there can be no doubt that it was very fully 
reached. 
At first the botanic gardens would find a comparatively 
virgin field for their work, while at the same time transport 
from one country within the tropics directly to another was 
usually very difficult or impossible. It was thus more or less 
of a necessity to have a government institution to carry on 
such work in each country, and these institutions required to 
be coordinated by the establishment of some central garden or 
institution in Europe, as in the Britisch colonies they were 
coordinated by the opening of Kew. 
Starting under such favourable conditions, the botanic gardens 
of the tropics introduced many valuable and useful plants into 
the countries in which they were situated, and these plants 
often formed the basis of considerable industries, such as tea, 
cinchona, rubber, and many other things. 
Now as time went on, it was found more and more difficult 
to discover useful plants that could be introduced into a country 
which had an active botanic garden. The number of such plants 
is very obviously not unlimited, and so it gradually happened 
that practically all that could be, were introduced into, and 
acclimatised in a given country. And thus as time went on, 
the usefulness of the botanic gardens, judged by the standard 
that was set up at their establishment, of course steadily 
diminished. In the Ceylon gardens, for example, the great 
bulk of the useful plants had been introduced by 1880, and 
since then it has been possible to get but little that is of 
