200 ON THE ECONOMIC USES OP LEAVES. 



obstruct the inroads of wild beasts upon cultivated fields, more particu- 

 larly of elephants. In the interior of Ceylon, every field under culti- 

 vation must be watched during night, to prevent depredations which 

 would be made upon the crops, were these animals to have free ingress. 

 . "When burned, the coco-nut tree, especially the leaves, affords a large 

 proportion of potash, whence the washermen procure all the potash they 

 require by the incineration of different parts of the tree. Soap is very 

 little used by the native washermen of Ceylon. Boats are rowed with 

 the centre rib of the leaf, in which operation it forms a substitute for 

 paddles. The end of this part of the leaf when well bruised, and 

 thereby converted into a brush, is used for a variety of purposes, such 

 as whitewashing houses, &c. 



In British Guiana, the natives make a species of iEolian harp of 

 the stipe of the leaf of a coco-nut tree ; and some tribes split the 

 stipes ; and after rendering the split portions very thin, they are attached 

 together laterally by means of their silky grass, thereby forming a sail 

 for canoes. 



The foliage, that part of the palms which render them objects of 

 such beauty and elegance, generally forms a magnificent crown at the end 

 of the trunk. The leaves supported on petioles or leaf stalks, sheathing 

 at the base, are alternate, coriaceous, and often of such gigantic size, — 

 measuring as they do in some species, fifty feet in length, and eight in 

 width, — that they surpass in the latter respect those of any natural order 

 of plants. 



Their structure may be summed up in a few words : they are simple, 

 and furnished with a midrib, from which parallel veins branch off. This 

 structure best seen in some species of (Geonoma) G. simplicifrons, Wiild., 

 for instance, when it appears in all its normal simplicity is common to 

 all palms, but assumes in different species different forms, easily recog- 

 nised by accomplished botanists wont to look upon the vegetable king- 

 dom with a morphological eye, but not so readily traced by those who 

 have made only a limited progress in phytological studies. 



In some species, as for example, the species of Geonoma just quoted, 

 the blade of the leaves is quite entire, while in others, of which the 

 coco-nut may be cited as the type, it is cut into long segments (pinna- 

 tisect) giving it the appearance of the plume of a feather : occasionally, 

 in the genus Caryota, these segments are again divided (bipinnatisect), 

 their ultimate divisions resembling in shape the fin or tail of a fish. 

 The midrib in these three forms it must be observed, extendst hroughout 

 the whole length of the leaves ; when the contrary is the case — namely, 

 when the midrib is less developed, palmate or fan-shaped leaves are the 

 result. This, however, does not happen very frequently, for out of 582 

 known species only ninety-one have fan-shaped leaves. 



The leaves are green, generally on both sides, as in the different 

 species of Cbamaldorea, but occasionally on the under side of a silvery 

 white, as in the Copernicia miraguama, and C. cerifera. Sometimes the 



