INTRODUCTION. 27 



with the trees peculiar to more southern regions. 

 The meadows and pastures, especially those in the 

 vicinity of the sea and in the mountain-valleys, are 

 clothed with a brilliant verdure, which we in vain 

 look for in the other sections of the globe. 



The warm temperate zone, extending to 25°, pre- 

 sents in general a less beautiful vegetation ; for al- 

 though the heat is greater the humidity is less con- 

 stant. But it is in the torrid latitudes that Nature 

 displays all her magnificence. There the species of 

 tribes, which in other climates are herbaceous, be- 

 come shrubs, and the shrubs trees. Ferns rise into 

 trunks equal to those of pines in the northern regions 

 of Europe ; balsams, gums, and resins, exude from 

 the bark ; aromatic fruits and flowers abound ; and 

 the savage, as he roams the woods, satisfies his hun. 

 ger with the spontaneous offerings of the soil. Here 

 also are all the climates of the globe, and almost all 

 their productions united ; for, while the plains are 

 covered with the gorgeous vegetation of the tropics, 

 the lofty mountains display the forms that occur in 

 the colder regions, and the places intermediate in 

 elevation all the graduated transitions from these 

 to the warmest parallels. 



The vegetation of the seas presents much less di- 

 versity tlian that of the land. It is less luxuriant, 

 less elegant, less ornamented, and less productive of 

 substances directly useful to man. There is also 

 less distinction between marine plants of different 

 latitudes ; for the great currents of the ocean, and 

 other causes, render its temperature more equable 

 than that of the atmosphere. 



The numerous and diversified forms which plants 

 assume, their distribution over the globe, their 



