SUMMARY OF THE CONTENTS OF VOL. I. 



relative numbers of the prevailing families of plants. The plains 

 adjoining the Icy Sea, north of the limit determined by Admiral 

 Wrangel as that of the growth of Coniferse and Amentacese, are the 

 domain of cryptogamous plants. Aspect and physiognomy of the 

 Tundras, where the soil, which is perpetually frozen, is covered 

 either with a thick coating of Sphagnum and other mosses, or with 

 the snow-white Cenomyce and Stereocaulon paschale . 120 123 



Principal causes of the very different distribution of temperature in 



Y the European and American Continents. Direction and curvature 



of the isothermal lines, or lines of equal temperature, for the entire 



4 year, for the winter, and for the summer . . .123 136 



Are there any grounds for believing that America emerged later than 

 the Old Continent from the chaotic watery covering ? . 136139 



Thermic comparison of the Northern and Southern Hemispheres in 

 high latitudes 139143 



Apparent connection of the African sea of sand with those of Persia, 

 Kerman, Beloochistan, and the interior of Asia. On the western 

 part of Mount Atlas, and the connection of purely mythical ideas 

 with geographical traditions. Indistinct allusions to igneous erup- 

 tions. Triton Lake. Crater-like forms of a locality south of 

 Hanno's " Bay of the Gorilla Apes." Singular description of the 

 "hollow Atlas" from the Dialexes of Marinus Tyrius . 143149 



Notices respecting the Mountains of the Moon (Djebel al-Komr) in 

 the interior of Africa by Reinaud, Beke, and Ayrton. Werne's 

 instructive notice of the second expedition undertaken by the orders 

 of Mehemet Ali. The Abyssinian mountains, which rise, according 

 to Riippell, almost to the height of Mont Blanc. The most 

 ancient notice of snow between the tropics contained in the Inscrip- 



