GrUYOT on Carl Bitter. 51 



eral laws of distribution of heat, represented by his system of 

 isothermal lines, of the distribution of plants, as depending 

 upon the two main elements of climate, heat and moisture, 

 of the marine currents as modifyers of climate in similar lati- 

 tudes, were of general application to all parts of the globe. 

 His admirable labors on the tropical regions of the Western 

 Hemisphere had revealed to the scientific world the true na- 

 ture of that massive structure of the_ Andes, and of the vast 

 table lands of Mexico, so gigantic in their proportions and still 

 so simple when compared with the system of the Himalaya, 

 the Alps, and thu complicated nature of the plateau of Iran. 

 He had shown the decided preponderance of these huge eleva- 

 tions in mass of large portions of the earth crust over the nar- 

 row chains of mountains in shaping the characteristic structure 

 of the continents. He had demonstrated the intimate connec- 

 tion of these grand plastic forms with the rapid changes in the 

 climate, the plants, and the animal life, which are observed at 

 every step, when ascending their slopes, and delineated, in 

 vivid outlines, the various zones of ever-changing vegetation, 

 through which the traveller gradually passes from the luxuri- 

 ant forests and stifling atmosphere of the plains of the Amazon 

 to the bare or snow-clad paramos of the Andes. Instead of 

 the unmeaning uniformity suggested before Humboldt, by a 

 glance at the map of tropical America, we now see rising be- 

 fore our minds a series of richly colored pictures, a series of 

 physical regions, of well-defined geographical types. We see 

 how they owe their existence and their special characters to 

 these fundamental traits of the structure of the continent, and 

 to the powerful influence which that structure exercises on the 

 climatic conditions, and through them, on animated nature 

 and man himself. Here the boundless Llanos of the Orinoco, 

 alternately a burnt, dusty, and lifeless desert and a sea of 

 verdure, teeming with temporary life : there the Selvas of the 

 Amazon with their endless, impenetrable forests, their luxuri- 

 ant solitudes, as yet xintamed by civilized man, too powerful 

 in their exuberance of nature life, for the few scattered sav- 

 ages, the only tenants of these rich wastes. At mid-height 

 in the Andes, the happy regions around Ibague, Popayan, 

 Loxa, with their everlasting spring, their murmuring biooks, 

 their shady forests, and evergreen foliage ; on the broad sum- 

 mit of the Andes, between a double row of the highest volca- 

 noes of our planet, the cool, but healthy valleys of old Peru, 

 with their invigorating air, their open and cultivated plains, 

 their extensive lakes, their ancient civilized people of the In- 



