HANDBOOK 



OF 



BRITISH HEPATIOE. 



INTRODUCTION. 



The Hepaticae, or Liverworts, have always been 

 regarded as closely related to the Mosses, and in 

 olden times were associated with them. In consti- 

 tuting his alliances Lindley united them in his 

 Muscal Alliance, and this has since been maintained, 

 although there is sufficient distinction between 

 them to be recognized by the naked eye. The 

 most prominent and popular distinctions are that, 

 in the Hepaticae the capsule, or spore-bearing 

 apparatus, splits when mature into four valves ; 

 whereas in the Mosses the capsule remains entire, 

 and is closed by a lid, or operculum, which falls 

 away to permit of the escape of the spores. This 

 is a general character to which on both sides there 

 are some exceptions, since some few of the 

 Hepaticae are devoid of a four-valved capsule, and 

 amongst Mosses the Andreaceae possess a valvular 

 capsule. In another aspect, that of vegetation, a 

 difference is also recognized, in that the Mosses are 

 foliaceous, possessing a stem and leaves, whereas 

 the Hepaticae are most commonly foliaceous, but 



B 



