The Mason-Wasps 



surprise me greatly with their tenacious 

 memory of the spot where the pebble lay 

 supporting their nest and with their lack of 

 perspicacity in all that concerned the nest 

 itself, which was replaced by another, quite 

 different nest without making them inter- 

 rupt the work already begun. The Pelo- 

 paeus outdoes them in these aberrations: she 

 gives the last strokes of the trowel to an 

 imaginary dwelling, of which nothing but 

 the site remains. 



Has she, as a matter of fact, a more ob- 

 tuse intellect than the dome-builder? The 

 entomological tribe seems hardly to swerve 

 from a common stock of aptitudes; those 

 whom we consider the most richly endowed, 

 on the evidence of actions normally accom- 

 plished, show themselves as limited as the 

 rest when the experimenter disturbs the cur- 

 rent of their instincts. It is probable that 

 the Mason-bee would have committed the 

 same absurdities as the Pelopaeus, had I 

 thought of subjecting her, at a propitious 

 time, to a similar test. A plasterer by pro- 

 fession, she would, like the other, have plas- 

 tered the base of the nest removed from the 

 pebble at the right moment. My confi- 

 dence in the glimmer of reason which the 

 makers of theories attribute to the animal 

 ii6 



