Bramble-bees and Others 



colonized. The Bee, after lodging a small 

 number of males in them, hastens to leave 

 them. In the wide front-gallery, she can 

 stay where she is and still be able to turn 

 round easily, for her different manipulations; 

 she will avoid those two long journeys back- 

 wards, which are so exhausting and so bad 

 for her wings. 



Another reason no doubt prompts her not 

 to make too great a use of the narrow pass- 

 age, in which she would establish males, fol- 

 lowed by females in the part where the gal- 

 lery widens. The males have to leave their 

 cells a couple of weeks or more before the 

 females. If they occupy the back of the 

 house, they will die prisoners or else they will 

 overturn everything on their way out. This 

 risk is avoided by the order which the Osmia 

 adopts. 



In my tubes with their unusual arrange- 

 ment, the mother might well find the dilemma 

 perplexing: there is the narrowness of the 

 space at her disposal and there is the emer- 

 gence later on. In the narrow tubes, the 

 width is insufficient for the females; on the 

 other hand, if she lodges males there, they 

 are liable to perish, since they will be pre- 



i6S 



