64 HISTORI OP BRITISH FERNS. 



means a heap ; the intention being to indicate the variation 

 or change which occurs in the apparent arrangement of the 

 sori, from the distinct patches to the continuous lines in 

 which they are seen to be disposed, if examined at different 

 stages of development the change, after all, being only 

 apparent, and not real. 



ALLOSORUS CRISPUS, Bernhardi. The Rock Brakes, or 

 Mountain Parsley. (Plate V. fig. 1.) 



This elegant little plant, which has considerable first-sight 

 resemblance to a tuft of parsley, and is hence sometimes 

 called Mountain Parsley, grows in a dense tuft, throwing up 

 its fronds in May or June, and losing them in the course 

 of the autumn. The fronds average about six inches in 

 height, and are generally almost triangular, with a longish, 

 slender, smooth stalk. They are of two kinds ; both kinds 

 twice or thrice pinnate, and of a pale green colour. The 

 segments into which the fruitless fronds are cut, are more 

 or less wedge-shaped, and notched or cleft at the end. The 

 fertile fronds have the segments df an oval or oblong or 

 linear form. 



The divisions of the fertile frond have a slightly tor- 

 tuous midvein, producing simple or forked venules which 

 extend nearly to the margin, each, for the most part, bearing 



