The Mason-bees 



spot that differs In no wise from a host of 

 others in order to remember it quite well, 

 notwithstanding the fact that, as a miner re- 

 lentlessly pursuing her underground labours, 

 she has other matters to occupy her mind. 

 Could our own memory always vie with Hers? 

 It is very doubtful. Allow the Red Ant the 

 same sort of memory; and her peregrinations, 

 her returns to the nest by the same road are 

 no longer difficult to explain. 



Tests of this kind have furnished me with 

 some other results worthy of mention. When 

 convinced, by untiring explorations, that her 

 prey is no longer on the tuft where she laid 

 It, the Pompilus, as we were saying, looks for 

 It in the neighbourhood and finds It pretty 

 easily, for I am careful to put It In an ex- 

 posed place. Let us Increase the difficulty to 

 some extent. I dig the tip of my finger into 

 the ground and lay the Spider In the little hole 

 thus obtained, covering her with a tiny leaf. 

 Now the Wasp, while In quest of her lost 

 prey, happens to walk over this leaf, to pass 

 It again and again without suspecting that 

 the Spider lies beneath, for she goes and con- 

 tinues her vain search farther off. Her guide, 

 therefore, is not scent, but sight. Neverthe- 

 is6 



