or situated near the end of the previous year's shoots, alone developing 

 themselves ; this tendency of the vine to continually elongate itself 

 must be carefully considered when vines are pruned long. 



The structure of the stem is very similar to that of the root. It 

 also commences, like the root, by being purely cellular, but soon 

 differentiates itself, becoming gradually more and more complicated. 

 In the centre we have a cylinder of pith, very considerable in the 

 young shoots, but which gradually diminishes as the shoot gets older. 

 Outside this several concentric layers of fibre-vascular bundles are 

 situated, the number varying with the age of the vine; they constitute 

 the wood, which is extremely hard and dense in old vines, although 

 soft when the shoots are young. Then comes the cambium, or 

 generating layer, which forms the rings of new wood every year. 

 The cambium layer is composed of mucilaginous cells, and is situated 

 immediately between the young wood and the bark, which is itself 

 composed of several layers, which it is unnecessary to enumerate 

 here. The bark is thin and adherent ; it is drier and tougher than 

 that of most other plants, and for this reason the vine is very hardy, 

 and capable of resisting intense cold ; it will survive a winter during 

 which the fig, for example, would perish. The outer layer of bark is 

 gradually pushed off and replaced by new layers underneath it. The 

 old ones do not fall off entirely, but remain more or less attached to 

 the under parts, thus giving the old wood of the vine a characteristic 

 but untidy appearance. This peculiar bark is a certain protection to 

 the plant, but is at the same time a great drawback, as it forms a 

 harbour for insects, spores of parasitic fungi, &c., &c. 



LEAVES. 



The leaves of the vine are large, and more or less dee*ply indented, 

 being usually divided into five lobes, by as many sinus, as the indenta- 

 tions are called. The margin is serrated or divided into teeth, which 

 vary greatly in size and character ; they are large or small, blunt or 

 sharp, regular or irregular ; sometimes there are two distinct series 

 of them. 



The leaf is supported by a rather long stalk or petiole, which in 

 structure resembles the young stem of the vine. There are five fibro- 

 vascular bundles in it, each of which separates at the junction with the 

 broad part of the leaf or limb to form one of the main veins, and 

 occupy one of the lobes, the centre one, or mid-rib, being the 



