Bramble-bees and Others 



home for her, which she is quite ready to 

 abandon should a better offer. Its expanding 

 cavity represents an average between the fa- 

 vourite small cylinder and the unpopular large 

 cylinder, which is accepted only when there is 

 no other obtainable. The first whorls of the 

 spiral are too narrow to be of use to the Os- 

 mia, but the middle ones have the right dia- 

 meter for cocoons arranged in single file. 

 Here things happen as in a first-class reed, for 

 the helical curve in no way affects the method 

 of structure employed for a rectilinear series 

 of cells. Circular partitions are erected at 

 the required distances, with or without a serv- 

 ing-hatch, according to the diameter. These 

 mark out the first cells, one after the other, 

 which are reserved solely for the females. 

 Then comes the last whorl, which is much too 

 wide for a single row of cells; and here we 

 once more find, exactly as in a wide reed, a 

 costly profusion of masonry, an irregular ar- 

 rangement of the cells and a mixture of the 

 sexes. 



Having said so much, let us go back to the 

 Osmia of the quarries. Why, when I offer 

 them simultaneously Snail-shells and reeds of 

 a suitable size, do the old frequenters of the 



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