study has convinced the Author that they are required. 

 He may have fallen inte error, but has earnestly endea- 

 voured to discover the truth. 



Attempts have recently been made greatly to reduce the 

 number of recognized species found in Britain ; but the 

 results obtained seem to be so totally opposed to the 

 teaching of the plants themselves, and the evidence ad- 

 duced in their fkvour is so seldom more than a statement 

 of opinion, that they cannot safely be adopted ; nor does 

 the plan of the present work admit of a discussion of the 

 many questions raised by them. Also it has been laid 

 down as a rule by some botanists, that no plant can be a 

 species whose distinctive characters are not as manifest m 

 an herbarium as when it is alive. "We are told that our 

 business as descriptive botanists is not " to determine what 

 is a species," but simply to describe plants so that they 

 may be easily recognized from the dry specimen. The 

 Author cannot agree to this rule. Although he, in common 

 with other naturalists, is unable to define what is a species, 

 he believes that species exist, and that they may often be 

 easily distinguished amongst living plants, even when se- 

 parated with difficulty when dried specimens alone are 

 esamined. He also thinks that it is our duty as botanists 

 to study the living plants whenever it is possible to do so, 

 and to describe from them, to write for the use and in- 

 struction of field- rather than cabinet-naturalists — for the 

 advancement of a knowledge of the plants rather than for 

 the convenience of possessors of herbaria, — also that the 

 differences which we are able to describe as distinguishing 

 plants being taken from their more minute organs is not a 

 proof that they constitute only a single species. It seems 

 to be our business to decide upon the probable distinctness 

 of plants before we attempt to define them — to make the 

 species afford the character, not the character form the 

 species. 



