180 HISTORY OF BRITISH TERNS. 



quickly lose their vitality,, and are cast off at the articulation 

 or joint near the base of the stipes, which occurs in this 

 family. The Alpine Woodsia, like its congener, grows in a 

 tufted manner, sending up several fronds from the crown, 

 from the base of which the dark-coloured wiry roots are 

 protruded. In form these fronds are longish and compara- 

 tively very narrow, almost linear, as it is termed ; and they 

 are pinnately divided into several roundish triangular pinnae, 

 which are shallowly lobed on the margin, and are usually 

 set on alternately along the opposite sides of the stalk or 

 rachis ; those towards the lower part are usually placed at a 

 greater distance apart than those near the upper end. They 

 are nearly smooth on the surface, and, in this respect, unlike 

 those of the kindred species, which have a much more hairy 

 appearance; small hair-like scales, in company with hairs, 

 are, however, present in both species. 



The midvein of the pinnae is indistinct, and throws out 

 venules into each lobe, these venules being more or less 

 branched according to the size of the lobes. The sori are 

 placed near the extremity of the venules, and are often 

 abundantly produced, so as to become crowded on the 

 pinnse. 



The Alpine "Woodsia is named W. alpina, by Mr. New- 



