Bramble-Dwellers 



judge better of future exits. The cocoons are 

 next laid out In one of the troughs. I sepa- 

 rate them with disks of sorghum, covering 

 both surfaces of the disk with a generous layer 

 of sealing-wax, a material which the Osmia's 

 mandibles are not able to attack. The two 

 troughs are then placed together and fastened. 

 A little putty does away with the joint and 

 prevents the least ray of light penetrating. 

 Lastly, the apparatus is hung up perpendicu- 

 larly, with the cocoons' heads up. We have 

 now only to wait. None of the Osmiae can 

 get out in the usual manner, because each of 

 them is confined between two partitions coated 

 with sealing-wax. There is but one resource 

 left to them if they would emerge into the 

 light of day, that is, for each of them to open 

 a side-window, provided always that they pos- 

 sess the instinct and the power to do so. 



In July, the result Is as follows : of twenty 

 Osmlse thus Immured, six succeed In boring a 

 round hole through the wall and making their 

 way out; the others perish in their cells, with- 

 out managing to release themselves. But, 

 when I open the cylinder, when I separate the 

 two wooden troughs, I realize that all have 

 attempted to escape through the side, for the 



28 



