XVll 



Medical opinion differs greatly in regard to the beneficial effect 

 of Sugar as an article of food ; many practitioners considering it 

 highly deleterious, especially to persons of dyspeptic habit, on ac- 

 count of its tendency to generate acid in the stomach. That it 

 fulfils, however, an important part in the nourishment of the 

 higher animals which subsist, either wholly or partially, on vege- 

 table substance, seems evinced by the natural fondness they exhibit 

 for plants in which it abounds. The destruction of our growing 

 seeds by birds is a consequence of their sweetness, one of the 

 necessary results of germination ; while the most nutritious Grasses, 

 and those best appreciated by grazing animals, are all among the 

 kinds which contain Sugar in the largest proportion. The enor- 

 mous consumption of fresh Sugar-cane by the negroes and natives 

 of the countries in which it is cultivated, and its effects upon the 

 former during the cane harvest, when, in many places, they 

 scarcely take any other kind of food, afford incontrovertible evi- 

 dence of the value of this vegetable production ; especially when 

 used in combination with the gluten and other proximate principles 

 that it accompanies in the juices of the plant, which is both masti- 

 cated in the raw state and eaten boiled as a culinary preparation. 



Apart from the utility of the Grasses as hitherto observed upon, 

 their importance in the economy of Nature, as constituting a large 

 proportion of the general vegetation in all countries, must not be 

 overlooked. This proportion varies greatly in regard to the num- 

 ber of species, according to climate, presenting its highest grade in 

 polar lands and descending as we advance towards the tropics. 

 Thus the Grasses form nearly one-fifth of the scanty flora of 

 Melville Island, in latitude 74° 46' N., while within the torrid 

 zone they scarcely average more than one-fifteenth. 



The verdant covering of our earth^s surface is associated with too 

 many circumstances necessary to animal existence, independent of 

 the food it furnishes, to admit of detail in this short treatise, in- 

 fluencing as it does, under its numerous modifications of forest. 



