b2 ON LEAVES. 



scales are short, hard, reddish, and rather hairy. In pro- 

 portion as they are more internal, they become membra- 

 naceous, pale-colored, and elongated ; small rudiments 

 of leaves then appear at their extremities ; and these, 

 shortly after assume the form of leaflets, so very different 

 in shape and structure from the external scales, that it is 

 difficult to conceive they have had the same origin. 



Emily. The more feeble and delicate the leaves of a 

 plant are, the greater, I suppose, will be the number of 

 those which degenerate into scales ; therefore, the thicker 

 and warmer will be the covering for the leaves which are 

 ultimately to be developed. 



Caroline. And these, being of the same delicate tex- 

 ture, require such an additional clothing. What an ad- 

 mirable effect produced from so simple a cause ! 



Mrs. B. These scaly leaf-buds are not universal, some 

 leaves being of so hardy a nature as not to require a cov- 

 ering, especially when growing in a warm climate : they 

 are then said to grow naked ; but being closely folded or 

 rolled up in a small compass when first they shoot, they 

 wear the appearance of a smooth bud without scales. 



The horse-chesnut, in its native climate of India, un- 

 folds its young leaves to the general atmosphere, without 

 risk of their suffering from exposure ; while, in this colder 

 country, many successive leaflets are arrested in theij 

 growth, and condemned to degenerate into scales. If you 

 examine the buds on this branch, you will see what num- 

 bers have changed their form, and are reduced to play <:. 

 subordinate part in the system of vegetation. 



The scales of some buds are formed from the rudimenU 

 of stipules ; others derive their origin from petioles o; 

 foot-stalks ; which, instead of growing long and slender 

 expand and assume the form of scales, and envelope the 

 embryo shoot. The buds of the waluut and the pear are 

 formed from stipulae. 



328. Of the buds of the ash and maple what is said! 329. li 

 what proportion does Emily suppose the leaves of a plant will be convert 

 ed into scales'? 330. Arc these scaly leaf buds universal! 331.- 

 How do those growing in warm climates appear when they first sho< 

 out! 332. What is said of the leaves of the horse-chesnut 1 33 

 How are the scales of different buds formed! 334. Of which clai. 

 are those of the walnut and the pear! 



