FERNS OF GREAT BRITAIN. 



Brake, the divisions are 

 also each rolled into 

 this form, and exliibit, 

 therefore, a number of 

 pale green curves, re- 

 sembling the shepherd's 

 crook. This mode of 

 unfolding is termed 

 cirdnate. Many exotic 

 ferns unfold in a dif- 

 ferent manner ; and two 

 of our wild genera, the 

 Moonwort and Ad- 

 der's-tongue, are with- 

 out the circinate ar- 

 rangement of their 

 young fronds. 



The mode in which 

 the fronds are traversed 

 by veins is termed their 

 venation, and it is usually so unlike the veining of an 

 ordinary leaf as to be at once characteristic of a fern ; 

 so that even when these plants are without their re- 

 productive brown clusters, one may always recognise 

 the green frond as that of a fern. By holding up a 

 young fern leaf to the light, it is easily perceived that the 

 veins in most cases have a forked character ; that is, they 

 branch off in pairs. Occasionally, indeed, one vein may 

 be seen running straight from the midrib to the margin, 

 without branching ; yet, in almost all instances, the vein 

 becomes forked almost immediately on leaving the mid- 



MOUNTAIN FERN. 



