Bramble-Dwellers 



depth. I need hardly say that, although these 

 lateral inroads are perceptible after the event, 

 they escape the eye at the moment when they 

 are being made. 



If we would witness them, we must slightly 

 modify the glass apparatus. I line the inside 

 of the tube with a thick piece of whity-brown 

 packing-paper, but only over one half of the 

 circumference; the other half is left bare, so 

 that I may watch the Osmia's attempts. 

 Well, the captive insect fiercely attacks this 

 lining, which to its eyes represents the pithy 

 layer of its usual abode; it tears it away by 

 tiny particles and strives to cut itself a road 

 between the cocoon and the glass wall. The 

 males, who are a little smaller, have a better 

 chance of success than the females. Flatten- 

 ing themselves, making themselves thin, 

 slightly spoiling the shape of the cocoon, 

 which, however, thanks to its elasticity, soon 

 recovers its first condition, they slip through 

 the narrow passage and reach the next cell. 

 The females, when in a hurry to get out, do 

 as much, if they find the tube at all amenable 

 to the process. But no sooner is the first par- 

 tition passed than a second presents itself. 

 This is pierced in its turn. In the same way 



22 



