58 OF LEAVES> 



Ijcaves with respect to Magnitude. 



Leaves vary in size, from the small leaves of some of the forest- 

 trees of om' climate, to the spreading Palms and Bananas of the tor- 

 rid zone. As we approach the torrid zone, the leaves increase in 

 magnitude ; we can, however, scarcely credit the reports of travel- 

 lers, who say, that the Talipot-tree, in the Island of Ceylon, produces 

 leaves of such size, that twenty persons may be sheltered by one sin- 

 gle leaf Although this account may be exaggerated, there is nd 

 doubt of the fact, that the leaves of the torrid zone are of a wonder- 

 ful size ; and that whole families, in those regions, can make their 

 habitations under the branches of trees. Here we see the care of a 

 kind Providence, which, in countries parched the greater part of the 

 year by a vertical sun, has formed such refreshing shelters. Mungo 

 Park, in his travels in Africa, remarksupon the many important uses 

 of palm-leaves ; serving as covering to cottages, baskets for holding 

 fruit, and umbrellas for defence against rain or sun. These leaves 

 answer as a substitute for paper, and were so used by the eastern 

 nations. Many suppose that the scriptures of the Old Testament 

 were originally committed to ])alm-leaves. 



The magnitude of leaves often bears no proportion to the size of 

 the plants to which ihey belong. The oak, and other forest-trees, 

 bear leaves, which appear very diminutive, when compared with 

 those of the cabbage, or burdock. 



Leaves, with respect to Duration, are. 



Caducous, such as fall before the end of summer ; 



Deciduous, falUng at the commencement of winter ; this is the case 

 with the leaves of most plants, as far as 30' or 40" from the equator; 



Persistent, or permanent, remaining on the stem and branches 

 amidst the changes of temperature ; as the leaves of the pine and 

 box; 



Evergreen, preserving their greenness through the year ; as the fir- 

 tree and pine, and generally all cone-bearing and resinous trees ; 

 these change their leaves annually, but the young leaves appearing 

 before the old ones decay, the plant is always green. 



In our climate, the leaves are mostly deciduous, returning in au- 

 tumn to their original dust, and enriching the soil from which they 

 had derived their nourishment. In the regions of the torrid zone, 

 the leaves are mostly persistent and evergreen ; they seldom fade or 

 decay in less than six years ; but the same trees, removed to our 

 climate, sometimes become annual plants, losing their foliage every 

 year. The passion-jflower is an evergreen in a more southern cli- 

 mate. 



Leatts with respect to Colour^ 



Leaves have not that brilliancy of colour which is seen in the co- 

 rolla or blossom; but the beauty of the corolla, like most other exter- 

 nal beauty, has only a transient existence; while the less showy leaf 

 remains fresh and verdant after the flower has withered away. 



The substance of leaves is so constituted as to absorb all the rays 

 of light except green; this colour is of all others best adapted to the 

 extreme sensibility of our organs of sight. Thus, in evident accom- 

 modation to our sense of vision, the ordinary dress of nature is of 

 the only colour upon which our eyes, for any length of time, can 

 rest without pain. 



But although green is almost the only colour which leaves reflect, 

 the variety of its shades is almost innumerable. 



Palm-leaves— Leaves not corresponding in magnitude to the size of the plant— Du 

 ration— fJolour of leaves— Different shades in the colour of leaves. 



