The Mason-bees 



guided by the wands of its antennae, never 

 blunders. Its choice is made. See it un- 

 sheathing its long instrument. The probe 

 points normally towards the surface and oc- 

 cupies nearly the central spot between the two 

 middle-legs. A wide dislocation appears on 

 the back, between the first and second seg^ 

 ments of the abdomen; and the base of the 

 instrument swells like a bladder through this 

 opening, while the point strives to penetrate 

 the hard clay. The amount of energy ex- 

 pended is shown by the way in which the 

 bladder quivers. At every moment we ex- 

 pect to see the frail membrane burst with the 

 violence of the effort. But it does not give 

 way; and the wire goes deeper and deeper. 



Raising itself high on its legs, to give free 

 play to its apparatus, the insect remains mo- 

 tionless, the only sign of its arduous labours 

 being a slight vibration. I see some perfora- 

 tors who have finished operating in a quarter 

 of an hour. These are the quickest at the 

 business. They have been lucky enough to 

 come across a wall which is less thick and less 

 hard than usual, I see others who spend as 

 many as three hours on a single operation, 

 three long hours of patient watching for me, 

 292 



