FERNS. 



149 



part of fibrous peat, one of loam and leaf-mould, and 

 one of silver sand. For large pots a quantity of 

 charcoal broken into pieces about the size of hazel- 

 nuts should he mixed with the soil, in order to more 

 thoroughly insui-e perfect drainage ; where charcoal 

 is not available broken potsherds will he found to 

 answer. Coarsely-ground bones mixed with the soil 

 suit the larger and stronger-growing species well. 



forming a distinct genus, viz., Zastrea. In another 

 large group the veins anastomose, that is to say, 

 they re-unite or pass into one another again by 

 means of branches. The only valid characters — those 

 by which the species of this genus may be recog- 

 nised and distinguished from ferns belonging to 

 other genera, perhaps similar enough in general 

 appearance to deceive a careless observer — are fur- 





/ V 





"^f'.'rSK --\ 



."O^ 



1-^ 







Nephbodium CusriDAiDJii. 



B'eplirodiuni. — As understood by the author of 

 the "Synopsis Filicum''' — the best standard work 

 from a purely botanical standpoint on ferns ever 

 published — the genus Nephrodmm embraces nearly 

 three hundred species, and is represented in almost 

 every fern country in' the world. AU have sub- ■ 

 globose sori, which are either dorsal or terminal on 

 the leaflets ; the involucre is more or less heart or 

 kidney shaped, and is attached by the sinus. Some 

 of the species vary very considerably in size, texture, 

 cutting, and venation. Our native Male Fern, Nephro- 

 dium Filixmas, may be taken as a type of a large 

 number having the veins all free, which were formerly, 

 and even now are by some botanists, looked upon as 



nished by the fructification, which is shortly described 

 above. N. ampbim, a native of the West Indies and 

 Central America, is a noble stove species, with a 

 stalk two to three feet long, densely clothed at base 

 with an entangled mass of soft, bright, silky scales 

 and fronds, three feet or more long, with a breadth at 

 base of two feet or more. N. cicatariwn is a widely 

 distributed species, occurring in a wild state through- 

 out tropical America, the Polynesian and Malayan 

 Islands, Himalaya, Ceylon, Mauritius, and in several 

 countries of tropical Africa ; the brownish stalks 

 measure a foot or more in length, and the nearly 

 triangular fronds, with sinuated lanceolate lobes, are 

 from one to two feet long. JV. cuspidatum, from 



