170 



THE UNIVERSE. 



tides of sand, which it afterwards expels by a brisk upward 

 movement, and this movement is repeated with such fre- 

 quency that the particles form an almost continuous jet. 

 When the sides of the funnel are so regular and sloping 

 that they cannot be climbed, the larva buries itself in such 

 a way at the bottom, that we see only the threatening 

 mandibles, which stand open, waiting for an opportunity 

 of being exercised. 



So soon as ever an ant stumbles over the edge of the 

 pit-fall it is inevitably borne down by the inclined plane 

 of the infernal tunnel. In vain does it try to rise again; 

 the sand yields beneath its feet and it rolls with fatal cer- 

 tainty to the bottom, where the terrible jaws of the ant- 

 lion at once seize and desjiatch it. 



Sometimes a larger insect falls into the deadly amlDus- 

 cade. It resists and tries vigorously to scale the slope 

 a^ain. In the meantime the treacherous ant-lion remains 



107. Pit of the Ant-lion — MiirmcUon formicarius. 



at its post, but dreading (from the bulk of the debris which 

 rolls upon its head) the size of the animal which has thus 

 lost its way, it now takes a direct part in its destruction, 

 and in order to impede its attempts,.launches in sv/ift sue- 



