HANDBOOK 



TO 



CRYPTOGAMIC BOTANY. 



INTRODUCTION. 



No general handbook to Cryptogamic Botany has appeared in the 

 English language since the Rev. M. J. Berkeley's in 1857. Since then 

 this department of botanical science has gone through little less than 

 a revolution. Not only has the number of known forms increased 

 enormously, but additions of great importance have been made to our 

 knowledge of structure by the use of the microscope, and to the genetic 

 connection of different forms by the careful following out of the life- 

 history of particular species. The present work is an attempt to bring 

 within the reach of botanists, and of the public generally who are in- 

 terested in the study of nature, an acquaintance with the present state of 

 our knowledge in this branch of science. It is not intended to replace 

 in any way the numerous excellent handbooks or monographs which 

 exist of special families or groups. Its scope is quite different. Neglect- 

 ing the minor differences by which genera, or in many cases even 

 orders, are distinguished from one another, the aim of the authors has 

 been to bring before the reader the main facts of structure, of develop- 

 ment, and of life-history, which mark the larger groups, contrasting them 

 with one another, and referring only to the broader lines of demarcation 

 within those groups. It is hoped that the work will be found useful to 

 the beginner as well as to the more advanced student. 



One great difficulty in our work has been to observe a due propor- 

 tion in the space allotted to the different groups ; and this has been in- 

 creased by the necessity for a very different mode of treatment in the 

 higher and the lower forms. Of the Vascular Cryptogams more nearly 

 allied in many respects to Phanerogams than to the lower Cryptogams 

 our knowledge is, with some exceptions, as minute and exhaustive as that 



