Instinct and Discernment 



dwelling than the Snail-shell. Nothing 

 tells us that the present-day generations are 

 not descended in the direct line from the 

 generations contemporary with the quarry- 

 man who lost his as or his obol at this spot. 

 All the circumstances seem to point to it: 

 the Osmia of the quarries is an inveterate 

 user of Snail-shells; so far as heredity is 

 concerned, she knows nothing whatever of 

 reeds. Well, we must place her in the 

 presence of these new lodgings. 



I collect during the winter about two 

 dozen well-stocked Snail-shells and install 

 them in a quiet corner of my study, as I did 

 at the time of my enquiries into the dis- 

 tribution of the sexes. ^ The little hive 

 with its front pierced 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 con- 

 ditions. I add an assortment of empty 

 Snail-shells, after carefully cleaning the in- 

 terior 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 



1 Cf. Bramble-bees and Others: chaps, iii. and iv. — 

 Translator's Note. 



171 



