APPENDIX 



rays struck the surface of the leaves of a plant on the ground after filtering 

 through the foliage of a dense forest. To the migration, then, of chlorophyll 

 from the superficial layers of leaves under the action of a strong light, 

 leaving the cells full of air, may be attributed the first origin of silvery 

 leaves, though possibly in other cases the necessity felt by leaves to 

 assimilate in localities where light was scanty and unequally distributed, 

 may have caused the chlorophjdl to accumulate in certain spots and to 

 absent itself from others. 



On the vividly- coloured leaves of plants living in shady places purple 

 and violet tints are often found to predominate. Such colours are caused 

 by special pigments, and to these the function of moderating the action 

 of light on chlorophyll has been attributed. But as such pigments 

 are frequent in leaves which grow in the shadiest places, where such a 

 function would be not only unnecessary, but harmful, the theory is one 

 which may well be called in question. It is a fact worthy of note that 

 the lower surface of the leaves is that which is usually more brightly 

 coloured. I am thus more inclined to believe that the violet pigments 

 may serve as a sort of sensitising filter to green rays, which are not very 

 active in assimilation. In fact the solar rays which have filtered through 

 a dense foliage are wanting in actinic rays, for these are absorbed by 

 green. The violet pigment may in a way make up for this deficiency 

 and excite and aid the assimilating energy. It does not, in fact, seem 

 too much to say that the protoplasmic granules, which in certain plants 

 and in special organs are charged with pigment, may be a sort of 

 embryonic stage of those organs which in more highl} 7 constituted 

 beings are those of vision. 



Various ground orchids belonging to the genera Ancectochilus, 

 Nephelophyllum, Vrydagzinia, Odontochilus, and especially Goodyera, 

 have purple, velvety, or metallic leaves, often with veins of a rosy, golden, 

 or silvery tint. Variegated with green and white are those of Schis- 

 matoglottis asperata albotnacidata, Engl., and of S. Beccarii albolineata, 

 Engl., amongst the Aracece ; of Pinanga variegata, Becc, amongst the 

 palms ; of Didymocarpus kompsobcea, C. B. Clarke, and D. Clarkei, 

 Becc. amongst the Gesneracece. Variegated leaves, too, are frequent 

 amongst the Acanthacece, and numerous are the tiny forest species of 

 this family which show the above-mentioned peculiarity. One species 

 (P. B., No. 889) is particularly remarkable for the marked contrast in 

 its leaves of a deep metallic green with silvery white and yellowish lines. 

 Very noticeable for their leaf-markings are two Riibiacece, an Argostemma 

 (B.P., Xo. 1658) and an A cr anther a (P. B., No. 3794). Amongst the 

 Marantacece the leaves of a Phrynum, which I discovered on the Bellaga 

 Hills (Ph. Zebrinum, Becc. P. B., No. 3785) are very beautiful ; they 

 are of a deep green with light lines, recalling those of Maranta Zebrina. 

 Another species of Phrynum (P. B., No. 1493), which I found on Mount 

 Mattang, has similar markings, but less distinct. One of the Cyperacece, 

 which I found in the dense shady forest on the slopes of Mount Mattang 

 has its narrow leaves green with metallic violet sheen (the only example, 

 I believe, of such a coloration in the entire family). It is a new 

 species of Mapania, to which the name M. versicolor is aptly given 

 (P. B., No. 1414 and 27). I have already recorded the singular example 



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