Bramble-bees and Others 



stones in which various Hymenoptera, inclu- 

 ding the Three-horned Osmia in particular, 

 take possession of the dead Snail-shell. 



The quarries form part of an extensive 

 plateau which is so arid as to be nearly de- 

 serted. In these conditions, the Osmia, at all 

 times faithful to her birth-place, has little or 

 no need to emigrate from her heap of stones 

 and leave the shell for another dwelling which 

 she would have to go and seek at a distance. 

 Since there are heaps of stone there, she prob- 

 ably has no other dwelling than the Snail-shell. 

 Nothing tells us that the present-day genera- 

 tions are not descended in the direct line from 

 the generations contemporary with the quar- 

 ryman 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 instal them in a 

 quiet corner of my study, as I did at the time 

 of my enquiries into the distribution of the 

 sexes. The little hive with its front pierced 



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