xvni THE CRATERS OF THE RIFT VALLEY 229 



Canyon of Arizona, a mighty gorge usually attribuU-d 

 to erosion. 



Several writers hold the opinion that the Rift Valley 

 represents a portion only of an extensive depression 

 which contains the Jordan Valley, the Dead Sea, the Red 

 Si -a, and the Gulf of Aden. In Africa this depression 

 continues a south-westerly course until it reaches Lake 

 Rudolf. It then divides ; the western arm of the valley 

 curves around the Victoria Nyanza and ends in the 

 district of Lake Nyasa. The two arms of this huge 

 trench are separated by 6 of longitude. The other 

 shorter, or eastern arm, runs directly south, following the 

 36th meridian of longitude, terminating in German 



CJ ' O 



Territory. It is this eastern arm with which we are 

 concerned. The Victoria Xyanza lies in the area 

 included between its eastern and western arms. 



There is geological evidence to show that great earth 

 movements have happened along this Rift Valley at a 

 recent date, which makes it probable that native 

 traditions of great changes in the structure of the country 

 are recollections of geographical events. Gregory also 

 points out that, if all the air and water were removed 

 from the earth, this huge rift would present much the 

 same aspect to an inhabitant of the moon as some of the 

 larger lunar rills present to us. 



As bearing on the question of the geological relation- 

 ship of the Palestine to the African section of this valley 

 Gunther's opinion may be mentioned ; that the fishes 

 found in the system of the Jordan present so many 

 African types that they must be included in a 

 description of the Ethiopian region. This points to an 

 original connection between the rivers of Palestine and 

 Central Africa. The infusion of African forms in the 

 Jordan cannot be accounted for by any of the accidental 

 means of dispersal. The depression which contains the 

 River Jordan, the Sea of Galilee, and the Dead Sea, 

 known as the Jordan-Arabah Valley, displays abundant 

 evidence of volcanic action. 



