EXPLANATION OF PLATE IV. 



Fig. a, branch showing the terminal spring shoot of the season with characteristic, large silvery white winter 

 bud ; the bundles of leaves arise from the axils of the leaf-bracts of the last two seasons, the iirst leaves of the second 

 year already shed ; t>, detached bundle of mature leaves with sheath ; c, d, scales of the sheath, magnified three and 

 nine times; e, transverse section through base of leaf bundle showing imbrication of sheath scales, magnified 30 

 diameters; /, transverse section of an immature leaf, magnified 30 diameters; g, transverse section of a mature leaf, 

 magnified 45 diameters, showing the microscopic structure (as pointed out for P. erliinata,f,f); A, longitudinal sec- 

 tion of the dorsal side of a mature leaf showing two rows of stomata and the serrated edge, magnified 45 diameters. 

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