50 



LEAVES. 



Fig. 58. 



Fig. 59. 



i^.i 





'» M. 





Fig. 58, A, is quaternate ; tlie leaflets are ctinei- Fig. 60. 



form, very entire. B, a miinosa leaf ; it is twice hi- 

 nate. C is equally pinnate ; with six pairs of pmnce. 



Fig. 59, a, is interruptedly pinnate, the pinnae be- 

 ing dissimilar in size, b is unequally pinnate ; the 

 leaflets are stipuled. c represents the compound 

 leaf of a fern ; it ispnnnate ; the stipe or rachis large 

 and compressed. 



Fig. 60, at a, is cylindrical, and fistulous, as in the 

 onion, where the vascular and cellular tissues are de- 

 veloi^ed so as to form a circle with a cavity in the center, b is afcshy leaf, deltoid 

 and dentate, c, a leaf which is sub-ovate, and bearded at the summit. 



N"oTE. — It is recommended to the pupil to practice drawing the various leaves 

 which are given for examples ; and to collect as Jiiauy specimens of leaves as pos- 

 sible. 



57. Leaves vary in magnitude^ from the small leaves of some 

 of the forest-trees of our climate, to the spreading Palms and 

 Bananas of the torrid zone. As we approach the torrid zone, 

 the leaves increase in magnitude. 



a. We can, however, scarcely credit the reports of travelers, who say, that tha 

 Talipot-tree, in the Island of Ceylon, produces leaves of such size, that twenty per 

 sons may be sheltered by one single leaf. Although this account may be exagger- 

 ated, there is no doubt of the fact, that the leaves of the torrid zone are of a 

 wonderful 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, remarks upon 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. The magnitude 

 of leaves often bears no proportion to the size of the plants to wl)ich they belong. 

 The oak, and most other forest-trees, bear leaves, which appear very diminutive. 

 when compared with those of the cabbage, or burdock. 



58. Leaves, with respect to Duration^ are, Fugacious ^^'hen 

 they fall early, or soon after their first appearance. Deciduous^ 

 falling at tlie commencement of winter ; this is the case with 

 the leaves of most plants, as far as 30° or 40° from the equator. 

 Persistent^ remaining on the stem and branches amidst the 

 changes of temperature; such plants are called Evergreen *, as 

 the fir-tree and pine, and generally all cone-bearing and resin- 



57. Vanrxtwn in the PTze of leave^^ — a. Leavo* of the torrirt zone. — 58. Duration of leaves. 



