50 THE GRASSES. 



this instance, and perhaps generally, no necessity for 

 the aid of insects to assist the fertilization of the Mo- 

 noecious or Dioecous plants. Nature is all sufficient for 

 the purposes she intended, and never could have left 

 the perpetuation of existence, either wholly or partial- 

 ly, even in plants, to the uncertain and accidental aid of 

 animals. 



The general aspect of the Grasses is so similar, 

 and so well understood by all observers, that it is nearly 

 superfluous to enter into any general definition for the 

 Tyro. They vary in duration ; those most useful to 

 man, such as grains, are only annual, or perish when 

 they have matured their seed, so that perpetual indus- 

 try, in providing for their existence, is so much a human 

 requisition, that, as far as we yet know, Wheat, Oats, 

 and Maize, are extinct as wild plants, and now owe 

 their being entirely to that stage of human society, 

 which they so eminently assist to support. 



But the greatest number of Grasses are perennial, 

 or exist for an indefinite period, and annually die to 

 the ground. A few in mild or tropical climates only 

 are supplied with woody or enduring stems ; such are 

 some of the Reeds, the Sugar-cane, the Cane of the 

 western and southern parts of the United States, and 

 the Bamboo, which becomes so large a tree as to af- 

 ford a canoe from half of a culm, as the Botanists call 

 the stems of all the Grasses; their joints or articula- 

 tions are also called nodes, and from this point alone 

 they produce their leaves and buds. The interior of 

 the culm, in the cane, often produces a secretion of 

 flinty liquor, and the whole epidermis, or outer sur- 

 face of Canes and Grasses, is in reality glazed with a 

 thin siliceous coating, which in the woody stems rea- 

 dily blunts the edge of a knife. 



The leaves of this tribe are arranged along the 

 stem in an alternate order, and attached by means of 



