CHAPTER VIII. 



GOLD AND SILVER FERNS. 



HESE form a most interesting section, which is composed 

 exclusively of plants of exotic origin. All of them possess a 

 certain and constant charm even to the most uninitiated, who 

 generally look upon them as marvels of creation. The gold or 

 silver character of these Ferns is formed by different substances, 

 and is due to various natural causes. In the majority of cases, such as in 

 Gymnogrammes, in Adiantums, and in Nothochlaenas, it is produced by a 

 thick coating of fine powder forming a sticky substance, resembling a waxy 

 exudation, with which the under side of the fronds is entirely and evenly 

 covered ; in other instances, such as in Cheilanthes, the under part of the fronds 

 is rendered equally silvery by the superposition of scales or of hairs which 

 uniformly cover their surface ; while in the case of Silver Tree Ferns, and in 

 some of the Gleichenias, the under side of the fronds, though deprived of either 

 scales or real powder, is beautifully and evenly silvery, as if only painted 

 white, or of a glaucous colour. But in their cases this white or glaucous 

 colour is simply due to the presence of a substance of a consistency similar 

 to that of the bloom on grapes and plums, and disposed in a coating so fine 

 that it readily disappears when rubbed with the fingers. This substance, 

 although quite superficial, is, however, laid very evenly, and forms, with 

 the other portions of the leafy part of the fronds, a perfectly united body. A 

 beautiful golden appearance is also frequently produced by the presence of 

 spores, which, when disposed in sufficient quantities, give the fronds a 

 brightness equal to that resulting from either of the above-named causes ; 



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