CHAPTER III. 



THE BLADDER FERNS. 



I. THE BRITTLE BLADDER FERN. 



Cystopteris fragilis. 



'TpHE name given to the delicate and beautiful 

 ferns included under the genus Cystopteris, 

 is on account of the bladder-like coverings of the 

 spores on the backs of their fronds. The fragile 

 Bladder Fern is ordinarily seen about six inches 

 in height ; but it sometimes grows to the height 

 of a foot or more. The frond-stem is tender, 

 herbaceous, and very brittle, having just a few 

 light-coloured scales at its base. The fronds grow 

 from a tufted root-stock, and come up in clusters : 

 the crown of the root-stock spreading to admit of 

 this. The shape of the frond is lance-like, tapering 

 slightly to the base, as well as tapering gradually 

 to a point at the top. The lowest pair of branches 



