PARTS OF FERNS. 



S I INTEND generally to use the ordinary scientific terms, partly for con- 

 ciseness and partly to accustom my readers to them so that they may 

 understand them when they meet with them elsewhere, I shall now describe 

 the several parts of ferns by name, beginning from below and working 

 upwards. What non-scientific persons are apt to regard as the root of a 

 fern is called the rhizome (ri-zo-me). It is not a root, however, but analo- 

 gous to the butt or bole of a tree, or the creeping stem of an ivy, the real 

 roots being threadlike fibres of varying thickness, which grow out of it, and 

 which are generally clothed, par-ticularly at their ends, with a sort of short fur, by 

 means of which they absorb moisture for the nourishment of the plant. The rhizome, 

 particularly when it creeps or is otherwise elongated, is usually similarlv clothed. 



Rhizomes are of various kinds. The simplest form is that which grows " erect" 

 and produces its fronds in a crown or tuft at the top ; in which case the plant is called 

 a " crowned" or " tufted" one. In many ferns, this erect rhizome is prolonged above 

 ground to a great height, as in tree ferns, and it is then called a " caudex." This 

 caudex (plural, " caudices") is alwavs clothed with fibrous rootlets by means of which 

 moisture is imbibed from the atmosphere and helps the upward growth of the plant. 

 The number of fronds which form the crown of the plant depends very much on the 

 number of these aerial root fibres, our Dicksonia fibrosa, for instance, in which the 

 actual caudex is only about two inches thick, while the fibres form a felted or inter- 

 woven mass, sometimes two feet in diameter, having often as many as forty fronds in 

 its crown. Some caudices have a large conical base of root fibres ; and in others this 

 Gone extends to the very top of the caudex, which is then of no great height, the whole 



