PEOFESSOE TYNDALL ON THE VEINED STEUCTUEE OF GLACIEES. 
305 
the letter a stands in the diagram. The glacier descending from the Col is bounded on 
the west by the small moraine and between h and the side of the valley is another 
little glacier derived from one of the lateral tributaries. 
Fig. 23. 
With regard to the “ dirt-bands,” the following significant fact at once revealed itself. 
Tlie dirt-hands extended over that portion of the Glacier du Geant only which lay between 
the moraines a and or, in other words, were confined to the ice which had descended 
the great cascade between Le Rognon and La Noire. It was perfectly evident that the 
cascade was in some way the cause of the bands. 
The description which I have already given of the ice-fall of the Rhone and of the 
Strahleck arm of the Lower Grindelwald glacier, applies generally to the fall of the 
Glacier du Geant. The terraces, however, are here larger, and the protuberances at the 
base of the fall of grander proportions. These latter are best seen from a point near A 
upon the Glacier du Geant; they are steepest on that side, in consequence of the 
oblique thrust of the western tributaries of the glacier. All that I have said regarding 
