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ANATOMY, AND LIFE-HISTOBY OF THE CONIFERS. 



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formed rhythmically in some of the leaf -axils, while they are un- 

 developed in others. The sequence of the branches is generally as 

 follows : — Holding a branch in front of one and starting from a 

 median leaf, it will be seen that no branch springs from its axil ; 

 indeed, as a rule, the axils of the median leaves, whether anterior 

 or posterior, are empty. The lateral leaf next adjoiuing on the 

 left-hand side has a branch in its axil, which may therefore be 

 called fertile, while its neighbour on the right-hand side is sterile ; 

 the median leaves next above are, as usual, sterile ; above this 

 the left-lateral axil is sterile, the right fertile, and so on, the shoots 

 being produced at every second node, now on this side, now on 

 that. Variations of course occur, and the arrangement is masked 

 by the nearly equal size of the main and of the side- shoots which 

 produces an appearance of dichotomy, while the shoots appear 

 to proceed, on the same level, from both right and left axils. If 

 care be taken to distinguish between the leaf produced on the 

 main branch and that on the side branch next in order, which at 

 first sight appear to belong to the same axis, this fallacious 

 appearance may soon be detected. Often, as has been already 

 stated, shoots are produced on the side of the branch nearest to 

 the axis, but only on the off or distal side ; hence the branch 

 becomes curved, with its concavity turned towards the main 

 stem. Towards the apex of the branch the shoots are given off 

 on botli sides. On the long, quick-growing leader-shoots the 

 degree of concrescence of the leaves is equal in the median and in 

 the lateral leaves respectively; while on the more slowly growing 

 branches the concrescence of the base of the lateral is greater 

 than that of the median leaves. 



In Libocedrus dec ur reus the groups of branchlets constituting 

 branch-systems are placed vertically, so that the conduplicate 

 leaves, which are really lateral, are placed with their edges 

 looking upwards and downwards, while the flat median leaves 

 are directed laterally. Branching takes place with much regu- 

 larity from the axil of one leaf of every alternate pair, that is 

 from the axil of a lateral leaf, first on the left, then on the right, 

 and so on. 



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^vyagigantea.— This, as seen in English gardens in the young 

 state, is a pyramidal or flame-shaped tree, with the branch-systems 

 flattened horizontally, rarely vertically. The leaves are tetra- 

 stichous and decurrent. The ultimate branches are given off 



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