their number; and that though, like man, some are capable of existing in a great variety of climates, yet that these are to be considered as exceptions to a great and general rule. Within the tropics this limited distribution of plants is more remarkable than in the other zones. It is especially observable in the distribution of Palms, Scitamineæ, and the more valuable spices and aromatics. Heat alone is not sufficient for their production, or we should find them more general throughout the torrid zone, while, in fact, they are respectively confined to very narrow limits. Within the tropics, from the equator to nearly 20° N., and on the level of the ocean, or but slightly elevated above it, we distinguish a belt, within which are contained almost all the Palms with which we are acquainted. They constitute the most remarkable vegetable production within this space. As to distribution, we notice various points at which, without apparent alteration of temperature, they are respectively limited.

Of the Cocoa-nut we may remark, that it grows with the greatest luxuriance and perfection in the Maldive and Laccadine Islands, on the south and west coasts of Ceylon, on the coasts of Malabar and Coromandel, and west as far as Bombay. At Penang this Palm is evidently less productive, and therefore less extensively cultivated. It is replaced by the Areca catechu; by Nipa fruticans, Cycas circinalis, and a few others. The Sea Cocoa-nut, as it is called, is still more limited in its distribution; and the Borassus gomutus is almost equally so. Here, too, it is rare to see a single specimen of the Borassus flabelliformis, a palm so common in other parts of India. Peculiarity of soil does not appear to be the sole cause of the occurrence of some, or of the want of other species of the Palm tree. The soil of Penang and of the opposite coast is of various descriptions and qualities, and probably suited to the production of the whole tribe, being in some parts sandy, hard and poor; in others, of a stiff, iron-coloured clay; in others, soft and spongy, constituting extensive morasses; in others, thick, black, and rich, containing a large proportion of vegetable matter.