Bramble-bees and Others 



dwelling to the next if we would obtain a 

 complete census of her family. A spot of 

 colour, dropped on the Bee's thorax with a 

 paint-brush while she is absorbed in closing 

 up the mouth of the tunnel, enables 

 us to recognize the Osmia in her various 

 homes. 



In this way, the swarm that resided in my 

 study furnished me, in the first year, with an 

 average of twelve cells. Next year, the sum- 

 mer appeared to be more favourable and the 

 average became rather higher, reaching fif- 

 teen. The most numerous laying performicd 

 under my eyes, not In a tube, but in a succes- 

 sion of Snail-shells, reached the figure of 

 twenty-six. On the other hand, layings of 

 between eight and ten are not uncommon. 

 Lastly, taking all my records together, the 

 result Is that the family of the Osmia fluc- 

 tuates round about fifteen in number. 



I have already spoken of the great differ- 

 ences In size apparent in the cells of one and 

 the same series. The partitions, at first 

 widely spaced, draw gradually nearer to one 

 another as they come closer to the aperture, 

 which implies roomy cells at the back and 

 narrow cells In front. The contents of these 



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