INDUSTRIES OF ANIMALS. 



605 



servatories, and do not break them down. The walls of this 

 exterior enceinte a're hollowed by galleries of two kinds : some 

 horizontal and giving access from outside to all the stories, the 

 others mounting spirally in the thickness of the wall to the sum- 

 mit of the dome. When the colony is in full activity, after the 

 construction is completed, these little passages have no further 

 use. They served for the passage of the masons when building 



FIG. 8. SECTION OF A PALACE OF THE TERMITES. 



the cupola, and they could be utilized again if a breach should be 

 made in the wall. At the lower part these galleries in the wall 

 are very wide, and they sink into the earth beneath the palace to 

 a depth of more than 1*50 metre. 



These subterranean passages are the catacombs of the Ter- 

 mites, and have a very close analogy with those of old and popu- 

 lous human cities. Their origin is similar; they are ancient 

 quarries. The insects hollowed them in obtaining the necessary 



