Page:Popular Science Monthly Volume 73.djvu/206

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POPULAR SCIENCE MONTHLY

tropics are a region of big things and the herbaceous plants make little impression on the visitor. At the Peradeniya garden, the writer noted a small area of perhaps half an acre that had been neglected for a time. Here, although there were many tree seedlings started, there was a fairly good patch of weeds—enough to make a lonely American feel quite at home. These weeds were chiefly Lantanas and some of our American composites, particularly the fleabane Erigeron and also Conyza.

It would be difficult to find elsewhere in the world an area the size of Ceylon, or even much larger, with so many different vegetation regions. The differences in these regions are brought about largely by

Fig. 6. Laboratory and Herbarium. At the far right is the office of the director. From a photograph by the author.

the winds which determine the distribution of rainfall and by altitude with consequent temperature changes. The wet weather comes with the rains from two different directions. The northeast monsoon commences in October and brings heavy rains throughout the higher parts of the island and in the lowland country of the northeast. A series of rains continues through November and December, with a rather light rainfall during January, February and March. In April the wind changes to southwest and there is more rain, with June especially wet. From then until October the rainfall is again lighter. It will be seen then, that in the highlands it is always moist, but that there are certain districts which have a rather pronounced dry season. The driest parts of the island are in the north and the south or northwest and south-