Cuarrzr II. 
THE STRUCTURE AND ARRANGEMENT OF 
BRITISH GRASSES. 
In giving descriptions of grasses, it may be well to set out 
with the acknowledgment that these plants form an exceed- 
ingly natural group, which at once supposes that, although 
they have such differences that species can be recognised 
by careful analysis, they have yet such agreement in com- 
mon that the most casual observation is usually sufficient to 
determine one of the family to be a “ grass,’ or at least to 
enable us to refer it to the Graminacee, as the natural 
order of plants to which it belongs. 
Here, then, we see that there must be a great similarity 
of parts in species of grasses, and, as these parts are often 
minute, it follows that in order to understand descriptions 
so as to enable us to distinguish one species from another, | 
or to analyse them, great care must first be taken to master 
the minute distinctive characters which such parts may 
present. This done, the student of grasses may soon know 
them tolerably well, whereas, if neglected, he may attain to 
the knowledge of xames, but it will only be in a traditionary 
manner, and therefore with a constant liability to error, 
according as his informer is well or ill acquainted with his 
subject. 
This Chapter is intended to illustrate the following sub- 
jects :— 
1st. An account of the structure of grasses; and 
2nd. To offer a system of classification or arrangement 
dependent thereupon. 
1. Structure of Grasses—In grasses we meet with the 
following parts, all of which, though tolerably constant in 
c2 
