DEVELOPMENT AND DEATH OP LEAVES. 



193 



300. It not unfrequently happens that a plant will grow 

 under a considerable change of circumstances ; but will not form 

 its peculiar products in anything like the same perfection, as in 

 its natural condition. Thus, Tobacco may be raised in this 

 country, but it is far inferior to that of warmer and more sunny 

 climes ; as is also the scent of the Rose, which does not here 

 furnish enough of the very fragrant oil termed Otto of Roses, to 

 make it worth while to cultivate the plant for this purpose, 

 although the oil is imported from the East at an enormous price. 

 On the other hand, the common Lavender is more fragrant in 

 this country, than in the South of Europe. In general, plants 

 grown in warmer climates, where the sky is less clouded, form 

 secretions more active in every respect than those of temperate 

 regions ; substances, for example, which are more powerful as 

 medicines, or which have stronger and brighter colours, such as 

 make them useful as dyes. 



Development and Death of Leaves. 

 301. When leaves are first produced, 

 they are small, very delicate in texture, 

 pale in colour, and packed very closely to- 

 gether, forming what is called a leaf-bud. 

 Some of the outer ones are of firmer tex- 

 ture and darker colour, and fold over each 

 other like the tiles on the roof of a house, 

 so as to protect the soft and delicate organs 

 within. These are commonly termed scales, 

 being often very different from the true 

 leaves in aspect; but there is no real dis- 

 tinction between them ; for, on opening the 

 bud, it is easily seen, that their inner layers 

 gradually approach the true leaves, in ap- 

 pearance as well as in structure, and at last 

 pass almost imperceptibly into them. The 

 young leaves are most beautifully folded 

 together, in such a manner as to occupy the which bu(J s are 



FlQ - 7 4 - LEAF-BUDS 



ABOUT TO UNFOLD; a, a, 



least possible space ; and the peculiar mode 





