Bramble-bees and Others 



species in which we do not find this difficulty : 

 these are the Bees who keep to one gallery 

 and build their cells in storeys. Among the 

 number are the different inhabitants of the 

 bramble-stumps, notably the Three-pronged 

 Osmiae, who form an excellent subject for ob- 

 servation, partly because they are of imposing 

 size — bigger than any other bramble-dwellers 

 In my neighbourhood — partly because they 

 are so plentiful. 



Let us briefly recall the Osmia's habits. 

 Amid the tangle of a hedge, a bramble-stalk 

 is selected, still standing, but a mere withered 

 stump. In this the insect digs a more or less 

 deep tunnel, an easy piece of work owing to 

 the abundance of soft pith. Provisions are 

 heaped up right at the bottom of the tunnel 

 and an egg is laid on the surface of the food: 

 that is the first-born of the family. At a 

 height of some twelve millimetres,^ a parti- 

 tion is fixed, formed of bramble saw-dust and 

 of a green paste obtained by masticating part- 

 icles of the leaves of some plant that has not 

 yet been Identified. This gives a second 

 storey, which in its turn receives provisions 



lAbout half an inch. — Translator's Note. 



90 



