INTRODUCTION. vii 



of this work, by mentioning those Mosses of Germany, of France, 

 and of Lapland, which Britain was supposed not to possess, has 

 now been proved incorrect, by the subsequent discovery of several 

 of those very species ; whilst, on the other hand, some species 

 which we then considered peculiar to our islands, have recently 

 been detected on the Continent by the industry of the students of 

 Muscology. 



In France, including the vast extent of the Alps and Pyrenees, 

 Professor De Candolle has enumerated 227 species; but this 

 number must be far short of the truth ; for we know that our 

 friends, Mr. Arnott and Mr. Bentham, are in themselves able to 

 add considerably to this list. Germany, according to Mohr, reckons 

 rather more than 280 species; but to what extent Nees and 

 Hornschuch will increase the catalogue, we are unable to say, 

 since only a small portion of their valuable work has yet appeared ; 

 including merely their genera, Sphagnum, Phascum, Vbitia, 

 Pyramidula^ Schistidium, Schistostega, Gymnostomum, and Hy- 

 menostomum ; or, in other words, those genera which are desti- 

 tute of a true peristome to the capsule. These alone amount to 

 68; while the same division in Mohr, contains just half that 

 number ; so that another difficulty exists in estimating the com- 

 parative proportion of Mosses in different countries, even where 

 they have been best explored ; namely, the various opinions of 

 Botanists as to what are species, and what varieties, of these 

 plants; for every one is at liberty to exercise his own judgment 

 upon such points. Lapland, according to Wahlenberg's statement, 

 has 160 species; and Sweden, according to the same author, 226. 

 These are all the European countries of which any attempt has 

 been made at forming a Muscologia, and it must be remembered, 

 that all these writers, not even excepting Mohr, who has greatly 

 reduced the number of species made by preceding Botanists, 

 describe, as distinct individuals, many plants which we look upon 

 only as varieties. 



