Bramble-Dwellers 



The Leaf-cutting Bee (Megachile apicalis, 

 Spin.), who builds her leafy cups in the old 

 cells of the Chalicodoma of the Walls, acts 

 like the Solenius and directs her whole column 

 towards the same outlet. 



Incomplete as it is, this symmetry shows us 

 how unwise it were to generalize from the 

 conclusions to which the Three-pronged Osmia 

 leads us. Whereas some Bees, such as the 

 Anthidium and the Chalicodoma, share the 

 Osmia's talent for using the twofold exit, 

 others, such as the Solenius and the Leaf-cut- 

 ter, behave like a flock of sheep and follow 

 the first that goes out. The entomological 

 world is not all of a piece; its gifts are very 

 various: what one is capable of doing another 

 cannot do; and penetrating indeed would be 

 the eyes that saw the causes of these differ- 

 ences. Be this as it may, increased research 

 will certainly show us a larger number of 

 species qualified to use the double outlet. For 

 the moment, we know of three; and that is 

 enough for our purpose. 



I will add that, when the horizontal tube 

 has one of its ends closed, the whole string of 

 Osmiae makes for the open end, turning round 

 to do so, if need be. 



48 



