76 BEES AND WASPS [OH. 



to its host. I have never seen Anthophora offer any 

 resistance to Melecta, nor indeed take any notice of 

 its disreputable cousin. We can hardly imagine that 

 the bee knows that the egg she lays (if indeed she 

 knows that she lays an egg) in her cell is one day 

 destined to produce a bee like herself ; still less can 

 it be thought that she appreciates the fact that the 

 presence of Melecta involves disaster for at least one 

 member of her family. 



The bees of the genus Osmia are singularly ver- 

 satile in their habits, and adapt themselves with great 

 ingenuity to many very different nesting sites. Many 

 instances are recorded in which individuals of the 

 same species select an extraordinary variety of places 

 for their nests, thus sh owing that they are following 

 no blind instinct, but have some power of choosing 

 for themselves. For example, Osmia rufa (the 

 "Mason Bee"), a little bee about half an inch long 

 and covered with yellowish-red hairs, will sometimes 

 nest in the crevices of an old brick wall; at other 

 times it will burrow in the ground; at others it will 

 employ old snail-shells. In the Natural History 

 Museum at South Kensington there is exhibited a 

 flute within which 0. rufa had constructed fourteen 

 cells ; while in the Charterhouse School Museum 

 there is an outhouse lock which was entirely filled 

 up with the mud cells of this species during the 

 course of the summer holidays: I have also found 



