it INTRODUCTION. 



friend Mr. Drummond, of the Cork Botanic Garden, 

 who is prosecuting his researches with uncommon assi- 

 duity. We have adopted for the most part Hedwig's 

 terminology; but we have in general declined noticing 

 the male flowers, as they are generally called, not only 

 because we think their office or use is but imperfectly 

 known, but because they are with so much difficulty to 

 be discovered. 



We shall say a few words on the Genera of Mosses, 

 which, since the time of Linnaeus, who established only 

 six, have been varying as the species have been multi- 

 plied, and as the time and attention of botanists have 

 been more closely directed to them. Hedwig increased 

 the number of Genera to thirty-three, including the 

 exotic kinds. From them we have removed those whose 

 characters depend solely on the situation of the male 

 flowers, and have founded our characters, in the first 

 place, upon the absence or presence of the fringe of the 

 Peristome, which Hedwig employed to so much advan- 

 tage, and, following him, Turner and Smith ; 2dly, its 

 simple or double nature ; 3dly, its configuration and di- 

 rection ; 4thly, upon the lateral or terminal situation of 

 the fruitstalk ; and, 5thly and lastly, upon the form of 

 the calyptra, whether dimidiate or entire (mitriform), a 

 character we think of great importance, to which Mr. 

 Turner has long had recourse, but which was first pub- 

 licly brought into use by that eminent German Crypto- 

 gamist Mohr. By means of this we see many families 

 formed which are so in natural habit. Thus is Hed- 

 wig's slnictangium kept separate from Gymnostomum, 

 Grimmia from PFeissia, Trichostomum from Didy mo- 

 don, Zygodon from Orthotrichum, and Hookeria from 

 Hypnum. We think likewise that scarcely a less de* 



