SUMMARY OF THE CONTENTS OF VOL. I. 295 



the Sierra de Chiquitos) which separate the three plains of the 

 Lower Orinoco, the Amazons, and the Rio de la Plata . 106107 



On the dogs of South America ; both the aboriginal race and the 

 descendants of European dogs which have become wild. Sufferings 

 of cats when taken to elevations exceeding 13000 (] 3850 Eng.) 

 feet 107-112 



The low tract of the Sahara, and its relations to the Atlas Mountains, 

 according to the latest information given by Daumas, Carette, and 

 Renou. The barometric measurements of Fournel make it appear 

 very probable that part of the North African desert is lower than 

 the level of the sea. Oasis of Biscara ; abundance of fossil salt in 

 zones or bauds running from south-west to north-east. Causes of 

 the nocturnal cold in the desert according to Melloni . 112 118 



Notices of the River Wady Dra (l-6th longer than the Rhine, and 

 dry a large portion of the year), and of the country of Sheikh 

 Beirouk, a chief independent of the Emperor of Morocco, from 

 manuscript communications of the Naval Captain Count Bouet- 

 Villaumez. The mountains north of Cape Noun (a name used by 

 Edresi, in which, since the 15th century, an allusion to the negative 

 particle has been erroneously sought) attain 8600 (9166 English) 

 feet of elevation. . , t ........ . . . 118120 



The vegetation of the tropical American Llanos consisting of grasses, 

 compared with the vegetation of the North Asiatic Steppes con- 

 sisting of herbaceous plants. In the last-named Steppes, and 

 especially the more fertile among them, a pleasing effect is produced 

 in spring by small snow-white and red-flowering Rosacese, Amygda- 

 lese, species of Astragalus, Crown Imperials, Cypripedias, and 

 Tulips. Contrast with the desolate salt Steppes full of Cheno- 

 podiacese, species of Salsola and Atriplex. Considerations on the 



