io INTRODUCTORY. 



some cases being further marked off into varieties, which some 

 consider valid and some do not, while others hold that several 

 such varieties are permanent and distinct enough in their 

 characters to be of specific rank. Hence there is no generally 

 accepted list of British grasses. Bentham, for instance, has 

 101 species, Babington 127. 



In this book we have followed Bentham, for the following 

 reason. It is much better for anyone to compare specimens with 

 actual plants, and the most accessible collection of our native 

 grasses is in one of the swing cases in the Botanical Gallery at the 

 Natural History Museum at South Kensington, which anyone 

 at any time can see without having to ask for permission. In 

 this, as in many other collections, the plants are arranged in 

 Bentham's way, with Bentham's descriptions affixed, and the 

 advantage to the beginner of following the same system with the 

 specimens available was too obvious to be disregarded. 



In one small matter we have not followed Bentham or others, 

 and that is in the spelling of some of the specific names with a 

 capital. Throughout we have used a capital on y for genera, as is 

 now the custom in zoology, where the absence of the capital from 

 the beginning of a name proclaims at once we are dealing with 

 a species and not with a genus. The spelling of specific names 

 with a capital is merely a printer's custom which it is time should 

 become as obsolete in botany as in the sister natural science. 



Attempts have been made to identify our grasses by their 

 vegetative characters alone, but though some can be recognised 

 in that way, many cannot ; and owing to these exceptions the 

 attempt has failed in every scheme we have tried. We may 

 know a few grasses, but we cannot fit our knowledge into a key 

 that will serve for the group. We may, however, help on the 

 attainment of this very desirable object by making our descrip- 

 tions of such characters as full as possible, and that we have 

 done in our seventh chapter. 



