Permutations of Sex 



vented from issuing at the proper moment. 

 This would perhaps explain the mother's 

 hesitation and her obstinacy in settling fe- 

 males in some of my apparatus which looked 

 as if they could suit none but males. 



A suspicion occurs to me, a suspicion 

 aroused by my attentive examination of the 

 narrow tubes. All, whatever the number of 

 their inmates, are carefully plugged at the 

 opening, just as separate tubes would be. It 

 might therefore be the case that the narrow 

 gallery at the back was looked upon by the 

 Osmia not as the prolongation of the large 

 front gallery, but as an independent tube. 

 The facility with which the worker turns 

 as soon as she reaches the wide tube, 

 her liberty of action, which is now as 

 great as in a door-way communicating with 

 the outer air, might well be misleading and 

 cause the Osmia to treat the narrow passage 

 at the back as though the wide passage in 

 front did not exist. This would account for 

 the placing of the female in the large tube 

 above the males in the small tube, an arrange- 

 ment contrary to her custom. 



I will not undertake to decide whether the 

 mother really appreciates the danger of my 



169 



