58 MOSSES. 



urn is bordered by sets of teeth ; one set appears to belong 

 to the outside, and one to the inside. The urn generally 

 grows from a fleshy tubercle (apophysis), the station of 

 which is generally at the base of the flower-stem. . 



The secondary kind of fructification is only present in 

 some mosses ; it is formed of membranous cylindrical 

 bodies clustered in the axils of the leaves ; they open 

 irregularly at the point, and discharge a sticky fluid. 



Mosses are' among the first plants that spriDg up on 

 the surface of inorganic matter ; at first they appear like 

 a green stain, merely consisting of granulating seeds, but 

 soon clothing themselves with leaves, and then by their 

 decay producing the first deposit of vegetable matter 

 with which the soil is fertilized. 



The large group of Mosses, including several hundred 

 species, are divided into two great sections : first, the 

 summit fruited, where the fruit stem rises from the end of 

 the branch ; secondly, the side fruited, where it rises from 

 the side of the branch : but to these rules there are so many 

 exceptions, that we need rather to direct our attention to 

 the particular distinctions of the several groups. 



The first group of summit fruited Mosses is the An- 

 drsea group. It is characterized by one great peculiarity, 

 which has led scientific men to place it in an order by 

 itself. Its urn splits into four valves. These Mosses are 

 inhabitants of Alpine or sub- Alpine districts. They are 

 small plants, with blackish red foliage, which gives them 

 a burnt up appearance. The leaves fold over one an- 

 other in eight rows. 



Specimens of the Alpine Andraea have been given to 

 us from Ben Nevis ; the leaves are oval and pointed. 



