inSTTKOlDTJOTIODST. 



I. GENERAL SKETCH OF THE STRUCTURE OP 



MOSSES. 



In a work the primary aim of which is to enable the student 

 to identify and thence to classify mosses there is neither the need 

 of nor the room for a detailed account of their Morphology; this 

 will be readily obtained from works specially devoted to the 

 subject. A short sketch of the structure of mosses is not, how- 

 ever, out of place, and will if carefully read serve to familiarise 

 the student with the botanical terms necessarily employed in the 

 body of the work. In the following sketch my aim is to describe 

 the moss plant as it presents itself to a student examining it with 

 a view to its identification, with as little reference to microscopical 

 detail and to physiological and functional study as can be helped. 



General Characteristics of Mosses. 



The student is not likely to have any difficulty in recognising 

 a moss, as such, from any other class of plants, with the exception 

 of the very closely allied Hepatic^ or Liver-worts. Apart from 

 the fructification, which in the latter plants is of a widely different 

 structure (usually consisting of a dark globular capsule tipping a 

 slender, delicate, white fruitstalk and ultimately splitting into four 

 segments which spread horizontally into a cross), the Liver-worts 

 may as a rule be easily known by their vegetative structure, which 

 is generally of a more flaccid, delicate texture, the leaves when 

 present always very regularly imbricated, in the greater number 

 of species in two rows, one on each side of the stem, frequently 

 bifid or multifid, which is never the case with mosses ; always 

 nerveless, and always with a more or less hexagonal areolation — 

 characters which are rarely if ever found combined in any of our 

 mosses. There is a certain hardly describable facies about the 

 Liver-worts which serves to identify them better than any 

 description, and by which with a very slight experience the 

 student will be able to recognise them, with perhaps one or two 

 exceptions, at sight. 



