UNCLE IN ENGLAND. 127 



exceedingly useful in making us acquainted 

 with our own ignorance. She smiled, and put 

 the same question to Mary. 



Mary said, " I will do my best, but on con- 

 dition that you will tell me where I am wrong. 

 The stem is generally smooth, and its hollow 

 cylindrical form enables it to stand upright even 

 when four or five feet high ; it is usually jointed, 

 which gives it additional strength ; and it is 

 terminated by the flowers, which are either tufted, 

 or in spikes, or panicled: the leaves are al- 

 ternate, and always undivided one of them 

 springing from each knot, and enveloping the 

 stem with a sheath, which is split down to the 

 knot. All grasses have a chaffy flower inclosed 

 in a glume or husk ; and each flower has a 

 single seed. These are all the general characters 

 that I can recollect, which mark the tribe dis- 

 tinctly." 



" Very clear, indeed," said Miss Perceval, 

 " and quite full enough. The grasses are easily 

 distinguishable from all other plants, except the 

 Cyperacea ; and even they shew a well-marked 

 line of separation, as their stems are sometimes 

 triangular, and very seldom jointed ; and the 

 sheath is always entire, not split like that of the 

 grasses. 



" The grasses are of the greatest importance," 

 she continued, "in the economy of nature ; they 

 form in most countries the chief covering of 



