The Mason-Wasps 



allowed himself to be deceived by that 

 similarity in architecture, provisions and 

 habits; he thought that he was observing 

 Reaumur's Solitary Wasp, whereas in re- 

 ality his tube-builder presented specific dif- 

 ferences. 



We know the worker; it remains for us 

 to become acquainted with her work. The 

 entrance to the nest opens in the perpend- 

 icular wall of the bank. It is a round hole, 

 on the edge of which is built a curved tube, 

 with the orifice turned downwards. Made 

 with the materials cleared from the burrow 

 under construction, this tubular vestibule is 

 composed of grains of earth, not arranged 

 in continuous courses, but leaving small 

 vacant intervals. It is a species of open- 

 work, a lacework of clay. Its length is 

 about an inch and its internal diameter a 

 fifth of an inch. This portico is continued 

 by the gallery, of the same diameter, which 

 slants into the soil to a depth of nearly six 

 inches. Here this main gallery branches 

 into short corridors, each giving access to a 

 cell which is independent of its neighbours. 

 Each larva has its chamber, which can be 

 reached by a special passage. I have 

 counted as many as ten of them; and there 

 may be more. These chambers have no- 

 36 



