Mr. R. B. Hinds on Geographic Botany. 101 



1. They vary greatly in tlieir size or dimensions. — The largest 

 leaves are found among Endogena, where they are frequently 

 distinguished for their extent of surface. Aquatic plants have 

 often large leaves. Among terrestrial plants, some of the species 

 of MagnoliacecBy Melastomace<2 and Solanece are remarkable. 

 Lappa glabra, Heracleum spondylium, and Panax horridum have 

 large leaves for high latitudes. Within the tropics a great num- 

 ber of the leaves of shrubs and trees are compound, and veiy 

 frequently composed of a multitude of small leaflets, which give 

 a most pleasing appearance ; the numerous species of Mimosa and 

 Acacia usually possess them. In others these organs hardly 

 deserve the name of leaves : in Erica they are much contracted, 

 and in Pinus and Abies more resemble petioles destitute of 

 laminae, being in fact needle-shaped. In Tamariscinece, Casua- 

 rina and Ephedra, the leaves are reduced to scales or mere points. 



2. The outline, or method in which they are separated into 

 lobes or divisions. — Very striking is the appearance of that useful 

 tree the Artocarpus incisa, with its large leaves divided into deep 

 and numerous lacinise. Clustered as this tree is in groves around 

 the habitations of the natives, it conveys an aspect to the scenery 

 strictly Polynesian. As further instances may be mentioned 

 the species of Platanus, some Sterculice, and the characteristic 

 Carica papaya. 



3. As to consistence. — The leaves of herbaceous plants, espe- 

 cially those of the wet season of warm climates, are frequently 

 very soft and flaccid, and filled with a quantity of aqueous juice. 

 Evergreen trees have their leaves chiefly of a tough and leathery 

 consistence ; many of the trees and shrubs bearing this kind of 

 leaves are natives of subtropical regions, as the evergreen oaks, 

 many Phillyrecs, and Olea europcea. In some the mesophyll is 

 more than usually developed, as in Hoya carnosa ; and in the 

 members of Crassulacea and Ficoidece it is carried to excess in 

 their shapeless and succulent leaves. 



4. It would be difficult to describe the numerous shades of 

 green, though, when masses of vegetation are contrasted, they are 

 thrown out and become prominent. During the vigour of vege- 

 tation other shades are occasionally developed. In some species 

 of Fuchsia, Begonia and Amaranthus, the leaves possess a very 

 decided pink. Some have a silvery hue on their under surface, 

 though this appearance may be sometimes dependent on the 

 presence of hairs. It is chiefly in the autumn that leaves take 

 on their dififerent colours, and which are often excessively varied ; 

 but as Vitality is then ceasing, these appearances are rather 

 attendant on disorganization. 



5. As to the direction of their surfaces. — It is usual with ex- 



