6clvi INTRODUCTION. 



grasses, still, if certaia external characters should be found to indicate peculiar nutritive quali- 

 ties, the botanical description of any species of grass would not only convey a knowledge of its 

 external form, but likewise an idea of its value, as an article of food. That this would be pro- 

 ductive of much practical utibty, can hardly be doubted ; and the following particulars, stated 

 from the results of attentive observation, and numerous comparisons made in the course of the 

 experiments, and which gave occasion for the above remarks, may at least shew, that the sub- 

 ject is worthy of further investigation. m M 



1st, Grasses which have culms with swoln joints, leaves thick and succulent, and flowers 



with downy husks, contain greater proportions of sugar and mucilage. 



2nd, When this structure Ts of a light glaucous colour, the sugar is generally in excess. 



3rd, Grasses which have culms with small joints, flowers pointed, collected into a spike, or 

 spike-like panicle; leaves thin, flat, rough, and of a light green colour; contain a greater pro- 

 portion of extractive matter. .. , ' . 



4th, Grasses which have culms furnished with niimerous joints, leaves smooth and succu- 

 lent, flowers in a spike or close panicle, florets blunt, and large, contain most gluten and mu- 

 cilage. 



5th, When this structure is of a glaucous colour, and tlie florets woolly, sugar is in the next 

 proportion to mucilage, (No. II). 



6th, Grasses which have their flowers in a panicle, florets pointed or awned, joints of the 



4 



culm smooth, sheaths of the leaves hairy, leaves smooth and succulent, contain most mucilage 

 and extractive, 



7th, Grasses with flowers in a panicle, florets thinly scattered, pointed, or furnished with 

 long awns, culms lofty, with few joints, leaves flat and rough, contain a greater proportion of 

 saline matter and bitter extractive, 



8th, Grasses with strong creeping roots, culms few, leaves flat and rough, flower in a spike, 

 contain a greater proportion of bitter extract, with mucilage. 



m ' ' I 



The above general description of the figure, and properties of grasses, considers every part 

 of the plant, and is therefore termed the natural character of orasscs. 



The simplicity of form which runs through the whole structure of this order of plants, can 

 admit of but few very obvious variations to distinguish the different species from each other; 

 which indeed appears in the foregoing enumeration of terms that represent them. 



The parts of fructification, the flower, and the seed, are the least liable to vary from any 

 change of soil or cultivation, and Botanists have chosen them on that account, to fix their oe- 



ncric distinctions ; or when the flowers and seeds of any number of grasses agree in one or two 

 particular points, and differ therein from all the rest, such are termed a genera'or family. The 

 difference in the manner of inflorescence, and the form of clothing of the culm, leaves, and 

 roots, afford the specific characters, or separate the genera into species : when the difference 

 between two grasses' amounts to little else than one or two of these last-mentioned points, or 

 when such distinctions are either lost or found by raising the plant from seed, it is then consi- 

 dered a variety*. These characters of genera, species, and varieties; beino- founded on a few 



* When a variety retains those marks of distinction after being raised from seed, it is called a permanent variety; when it 

 loses those ajstinctions, it is then styled an accidental variety. 



