110 NATURAL HISTORY. [cH. VI. 



ture did not trust to its teeth alone ; but first voided 

 a liquid drop on the spot, and by this means soft- 

 ened the material which it wanted for use. Then 

 having- recourse to its teeth, it detached a morsel 

 from the mass, and taking it up in its two fore-legs, 

 kneaded it into a mortar. With such materials, and 

 so gathered, the insect commences its operations. 



In the following figure several tubes are seen 

 jutting out of the mass ; although formed with great 

 care and art, and evidently manifesting design, they 

 are not made to last ; they are no more than tem- 

 porary elevations raised over the excavation in the 

 wall or sand, and are destined to be destroyed as 

 soon as the latter is completed. 



a, b, c, d, e, exhibit the formation of the tubes in various stages. 



The little pieces of moistened sand and earth first 

 gathered, are placed in a circle, which serves to 

 mark out the dimensions of the hole. As the in- 

 sect continues to dig, it adds to the length of the 

 tube, and when it has completed the excavation, it 



