THE EUMENIDAE 301 



pellets nearer to the entrance than does 0. dorsalis, the 

 latter scattering them over a much larger area. We too 

 have seen an occasional nest of geminus without the turret, 

 but we attributed these cases to some accident, the intru- 

 sion of man or beast. We watched three such nests, whose 

 turrets had been destroyed, to see whether they would be re- 

 constructed, but no attempt was ever made by the wasps 

 to repair them. 



FIG. 55. Photograph of the nest of O. geminus, showing the mandible- 

 marks on the wall of the vertical channel. Natural size. 



Of course such a piece of work as this perfect little 

 chimney would be impossible without mud, whereas they 

 are usually built in dry, barren places. Hence this wasp, 

 like her sister 0. dorsalis, carries water and disgorges it 

 a little at a time, to wet the soil, making just enough mud 

 at a time for one pellet. 



We have never been so fortunate as to witness the begin- 

 ning of this pretty tower, but we have seen the builder 

 carrying out the pellets of mud through the chimney and 



