BRITISH FERNS. 95 



the summer months, and usually remain green through the 

 winter, turning completely black in the ensuing spring. 



The frond consists of alternately-branched veins, clothed with a 

 membranous wing, the margin of the wings being serrated : the 

 wing on the rachis is less apparent in Wilsoni than in Tun- 

 bridgense ; the pinnae are always convex above, while those of 

 Tunbridgense are usually flat : Wilsoni has a more erect habit, 

 Tunbridgense more horizontal, and, indeed, somewhat drooping, 

 so that, on the trunk of a tree, the fronds seem to rest one on 

 another like the tiles of a house. The receptacle is very 

 different from that of Tunbridgense ; it is elongate, swollen at the 

 base, and its exterior margin perfectly without serratures : when 

 the seed is mature, the receptacle opens at the top, and, splitting 

 down the middle, remains widely gaping. 



A comparison of the two illustrations, which are drawn with 

 considerable care, will enable the botanist to form a more correct 

 idea of the difference between them than I am able to convey by 

 any description : they are of the natural size, the detached 

 pinna of each being magnified. 



The Vignette represents a singular Holly-tree at Erwood, on 

 the banks of the Wye, between the towns of Hay and Bualt, a 

 district which has hitherto been but little investigated by the 

 botanists, but which appears to me to offer a rich return for a 

 very moderate labour. The river is very rapid, running through 

 the most beautiful woods, and over a bed of huge masses of stone. 



