during this extraordinary voyage. However, 

 in accordance with the adage which states 

 that necessity is the mother of invention, 

 we soon discovered that these beasts without 

 exception retreated in the face of fire, to 

 which they were entirely unaccustomed. A 

 supply of torches was kept in readiness as 

 weapons in the event of need. By the aid of 

 these, also, a better knowledge of the conditions 

 around us was obtained. The river was now to 

 all intents and purposes a subterranean stream 

 cutting through the accumulated remains of 

 dead sunlight^ seeking plants, which still lived 

 only far above, within range of the daylight, at 

 the upper surface of this dense mass of dead 

 and living vegetation. This lower zone through 

 which we now passed was not altogether com^ 

 posed of dead material, but supported abun^ 

 dance of saprophytic types, chiefy fungi and 

 bacteria. No human being could exist long 

 under these trying conditions, so that it was 

 with joy that, after two days, streaks of day^ 

 light began to penetrate the tangled mass above. 

 In a comparatively short time clear sky stood 

 above us, and the walls of rank vegetation on 

 either bank slowly dwindled as we proceeded. 

 With the return of daylight our spirits rose. 

 During the same day we witnessed a fight 



43 



