FERNS OF GREAT BRITAIN. 103 



of their tiny cases, M'liich are seen by the aid of a 

 microscope to be covered over witli markings so varied 

 and so delicate, that the hne of the finest pencil can 

 scarcely represent them. The finger of God has traced 

 them there, and left them to teU to us of His power 

 and skiU. 



Each pinnule of the Brake has a mid-vein, whence 

 issue side-veins, which are either opposite or alternate. 

 These are twice forked before reaching the margin, 

 where they unite with a vein which runs round the 

 edge, and forms the receptacle for the clusters of cap- 

 sules. The indusium consists of a white membranous 

 fringed expansion of the thin skin of the upper surface, 

 which rolls under so as to cover the fructification seated 

 on the marginal vein. Beneath this Hne of capsules 

 is another bleached and fringed membrane, very similar 

 to the first, which is also apparently an expansion of the 

 skin of the under surface. 



The following lines were written for this volume by 

 Mary Isabella Tomkins : — 



THE BRACKEN. 



As a coming screen grows the Bracken green. 



Up springeth it fair and free, 



Where in many a fold, grotesque and old, 



Twineth the hawthorn tree ; 



A covert meet from the noontide heat. 



For should you steal anear, 



You may chance discern, 'neath the spreading fern. 



The antlers of the deer. 



It boasteth a name of mystic fame. 

 For who findeth its magic seed 



