xiv PRELIMINARY REMARKS. 



food; but it seems extraordinary that tte various races 

 of mankind should have adopted grass-seeds as their 

 principal support, and pursued the cultivation of same 

 till it has become a science involving the subsist- 

 ence of millions, and engrossing the paramount con- 

 sideration of kings and governments. Equally singular, 

 in connection with some of the cereal grasses, is the 

 fact that neither change of climate nor treatment under 

 cultivation during thousands of years has brought any 

 important alteration in general character, so that the 

 cereal grasses grown under the rainless and burning 

 skies of Egypt and those of the same species grown in 

 Northern Europe differ no more than varieties which 

 may be reared on the same field. 



Every grass has its stem cylindrical and jointed at 

 intervals throughout, — the erect or ascending portion 

 (the culm or straw) being almost universally hollow 

 between the joints; and this applies irrespective of 

 stature— equally in the little Poa annua, which finds 

 a living, and even thrives, in the chinks between the 

 paving-stones of an unfrequented street, and in, for 

 instance, the Panicum arhorescens, which contends for 

 elevation with the loftiest trees of the forests of Hin- 

 dustan, through the branches of which its slender 

 stems, scarcely thicker than a goose-quill, penetrate 

 till they reach the upper air. 



We may make a rough division of the grasses in 

 the following way : — 



First. Those which are cultivated for the purpose of 

 using their seeds in the manufacture of food for man- 



