London Horticultural Society and Garden. 615 





pagne, Yellow champagne, Saunders's Cheshire lass, Red Turkey, Rum- 

 bullion, Cleworth's white lion, Denny's Shakspeare, Eckersley's jolly 

 printer, Ironmonger, Hebburn yellow Aston, Rival's Emperor Napoleon. * 

 Part ill. vol. i. of the new series of the Transactions was announced to be 

 ready for delivery to the Fellows of the Society; and it was announced 

 from the chair that, in consequence of the Society's meeting room being 

 about to undergo repair, the meetings will be suspended, by order of the 

 Council, until the 3d of October. 



Conclusion of Mr. Lindletfs Lectures on Botany as connected with 

 Horticulture. 



' Lecture IV. Leaves, Floivers, and Fruit. — The professor com- 

 menced by stating, that, as in his previous lectures he had confined himself 

 to those parts of a plant necessary to its stability, he should now proceed 

 to the organs which the stem and root were destined to support. These, 

 though under different modifications, were, in fact, the same, and he 

 should endeavour to ■ prove that leaves, flowers, and fruit were only 

 separate developements of the same organ, applied by nature to various 

 purposes, and under various forms. He would first consider leaves. 



He had already explained the manner in which leaves are contained in 

 buds, and the intervals at which they spring ; also, that every leaf has in 

 its axil a young bud imperfectly developed. This it was important to 

 remember, as he should afterwards have occasion to show that the pre- 

 sence of this axillary bud was one of the distinct characteristics of 

 leaves. Of the functions of leaves, he had also already spoken ; they are 

 employed to elaborate the sap forced up into them from the roots, and to 

 return it in its altered state to the tree. Without leaves, the process of 

 vegetation could not go on. Their intimate connection with the bark 

 might be easily discovered by tearing the petiole of a growing leaf from its 

 point of union with the branch, when it would be found that a portion of 

 the bark, and even of the alburnum, would usually be stripped off with it. 

 Leaves are of various kinds, but nearly all are comprised under two great 

 - divisions, the difference between which it is of great importance to be 

 aware of, as they afford distinct marks of the formation of the trees to 

 which they belong. A reticulated leaf, like that of the common rhubarb, 

 always serves to indicate an exogenous plant or tree ; and a parallel-ribbed 

 leaf, like that of the Yucca gloridsa, an endogenous plant or tree. The 

 professor observed that other differences were indicated by these leaves, 

 to some of which he should presently have occasion to refer. He now 

 directed the attention of his auditors to the different construction of these 

 leaves. The rhubarb leaf has large thick veins, called ribs, spreading out 

 like a fan, or the foot of a fowl, with smaller veins springing from the larger 

 ones, and crossing and recrossing each other angularly, in every possible 

 direction, like network ; while the Yucca has only a number of strong 

 parallel ribs, with short, slender, transverse lines between them ! and this 

 difference in the construction is found to exist almost invariably between 

 the leaves of exogenous and endogenous trees. In some particular 

 points all leaves agree. They are all formed of cellular substance, inter- 

 sected with air-passages, and are covered, except at the extreme point, both 

 above and below, with a cuticle composed entirely of cellular tissue. The 

 veins are protected by a coating of fibrous tissue, and are filled with spiral 

 vessels. The arrangement and shape of the cellular tissue and air-passages 

 which compose the main substance of the leaf vary in different plants ; 

 but the cuticle and the spiral vessels are present in all. Previously to 

 their developement, leaves are enfolded in the bud, and their disposition 

 (while in this state, which is called their prefoliation). differs in different 

 plants. All leaves have numerous pores, for the purpose of absorbing 



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