Bramble-bees and Others 



longer leaving the home but mounting guard 

 at the entrance to the burrows. No harvest- 

 ing- or pottery-work is possible with these ab- 

 sorbing doorkeeping-functions. Therefore 

 there is no new jfamily, even admitting that 

 the mothers' ovaries are not depleted. 



I do not know if a similar argument is valid 

 in the case of the Cylindrical Halictus. Has 

 she any general survivors? As my attention 

 had not yet been directed on this point in the 

 old days, when I had the insect at my door, 

 I have no records to go upon. For all that, 

 I am inclined to think that the portress of the 

 Zebra Halictus is unknown here. The reason 

 of this absence would be the number of work- 

 ers at the start. 



In May, the Zebra Halictus, living by her- 

 self in her winter retreat, founds her house 

 alone. When her daughters succeed her, in 

 July, she is the only grandmother in the es- 

 tablishment and the post of portress falls to 

 her. With the Cylindrical Halictus, the con- 

 ditions are different. Here the May workers 

 are many in the same burrow, where they 

 dwell in common during the winter. Suppos- 

 ing that they survive when the business of the 

 household is finished, to whom will the office 



448 



