XVIII THE CRATERS OF THE RIFT VALLEY 229 
Canyon of Arizona, a mighty gorge usually attributed 
to erosion. 
Several writers hold the opinion that the Eift Valley 
represents a portion only of an extensive depression 
which contains the Jordan Valley, the Dead Sea, the Red 
Sea, 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 
Territory. It is this eastern arm with which we are 
concerned. The Victoria Nyanza 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. 
