Bramble-bees and Others 



mia employ soft earth. This material is dif- 

 ferent from the Mason-bee's cement, which 

 will withstand wind and weather for many 

 years on an exposed pebble; it is a sort of 

 dried mud, which turns to pap on the addition 

 of a drop of water. The Mason-bee gathers 

 her cementing-dust in the most frequented and 

 driest portions of the road; she wets it with 

 a saliva which, in drying, gives it the consist- 

 ency of stone. The two Osmiae who are the 

 almond-tree's early visitors are no chemists: 

 they know nothing of the making and mixing 

 of hydraulic mortar; they limit themselves to 

 gathering natural soaked earth, mud in short, 

 which they allow to dry without any special 

 preparation on their part; and so they need 

 deep and well-sheltered retreats, into which 

 the rain cannot penetrate, or the work would 

 fall to pieces. 



While exploiting, in friendly rivalry with 

 the Three-horned Osmia, the galleries which 

 the Mason-bee of the Sheds good-naturedly 

 surrenders to both, Latreille's Osmia uses dif- 

 ferent materials for her partitions and her 

 doors. She chews the leaves of some mucila- 

 ginous plant, some mallow perhaps, and then 

 prepares a sort of green putty with which she 



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