222 NATURAL HISTORY. [CH. XIII. 



are all, one by one, placed upon its head, and jerked 

 beyond the outer margin of the excavation. But 

 when arrived near the bottom, it sometimes en- 

 counters a pebble too large to be removed even by 

 this process, its head not having sufficient breadth 

 and strength to bear so bulky and so heavy a sub- 

 stance : while the hole is too deep to admit of its 

 being projected over the margin. In this dilemma 

 the little engineer is not destitute of resources. A 

 new mode of proceeding is adopted, suitable to the 

 difficulty which the insect has to overcome. By a 

 series of the most ingenious movements, it con- 

 trives to lift the pebble upon its back, where it is 

 kept in a steady position by means of the segments 

 which compose that part. Having thus secured the 

 pebble from the chance of falling, the indefatigable 

 labourer resolutely walks, tail forwards, up the 

 slope of the excavation, and deposites its burden on 

 the outside. When the stone to be removed hap- 

 pens to be round, the insect's task becomes more ar- 

 duous and difficult : in this emergency, the proceed- 

 ings of the little ant-lion cannot fail to excite the 

 deepest sympathy. With incredible exertion it lifts 

 the pebble on its back ; it then commences its re- 

 trograde ascent up the slope of the den : but at every 

 step of its progress, the load may be seen to totter 

 to one side or the other ; but the expert porter ele- 

 vates the segments of its back in order to restore 

 the balance. It sometimes occurs, that, when it has 

 very nearly reached the top of the excavation, a 

 false step causes it to stumble : in this unlucky case, 

 all its efforts are frustrated, and the stone rolls 

 headlong to the bottom. Mortified, but not despair- 

 ing, the unwearied ant-lion returns to the charge ; 

 again places the stone on its back, and again as- 

 cends the sloping side, artfully availing itself of the 

 channel which had been formed by the rolling stone 

 the sides of this channel frequently serving to 

 support the load. Throughout the whole progress 



