Instinct and Discernment 



with forty holes has bits of reed fitted to it. 

 At the foot of the five rows of cylinders I 

 place the inhabited shells and with these I 

 mix a few small stones, the better to imitate 

 the natural conditions. I add an assortment 

 of empty Snail-shells, after carefully clean- 

 ing the interior so as to make the Osmia's 

 stay more pleasant. When the time comes 

 for nest-building, the stay-at-home insect will 

 have, close beside the house of its birth, a 

 choice of two habitations: the cylinder, a no- 

 velty unknown to its race ; and the spiral stair- 

 case, the ancient ancestral home. 



The nests were finished at the end of May 

 and the Osmiae began to answer my list of 

 questions. Some, the great majority, settled 

 exclusively in the reeds; the others remained 

 faithful to the Snail-shell or else entrusted 

 their eggs partly to the' spirals and partly to 

 the cylinders. With the first, who were the 

 pioneers of cylindrical architecture, there was 

 no hesitation that I could perceive: after ex- 

 ploring the stump of reed for a time and 

 recognizing it as serviceable, the insect in- 

 stals itself there and, an expert from the first 

 touch, without apprenticeship, without gro- 

 ping, without any tendencies bequeathed by 



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