The Hunting Wasps 



This supply is placed in front of the mouth 

 of the bag. The bag itself is in a horizontal 

 position, which is convenient for the coming 

 task. The larva, leaning half out of the 

 hammock, picks up its sand almost grain by 

 grain, rummaging in the heap with its mandi- 

 bles. If any grain is found to be too bulky, 

 the grub takes it and throws it away. When 

 the sand is thus sorted, the larva introduces 

 a certain quantity into the silken edifice by 

 sweeping it with its mouth. This done, it 

 retires into the eel-trap and begins to spread 

 the materials in a uniform layer on the lower 

 surface of the sack; then it gums the different 

 grains and inlays them in the fabric, using 

 silk as cement. The upper surface is built 

 more slowly: the grains are carried up one 

 by one and fixed on with the silken putty. 



This first layer of sand as yet embraces 

 only the front half of the cocoon, the half 

 that ends at the mouth of the bag. Before 

 turning round to work at the back half, the 

 grub renews its supply of materials and 

 takes certain precautions so as not to be hin- 

 dered in its mason's work. The sand out- 

 side, heaped up in front of the entrance, 

 might slip inside and embarrass the builder 

 in so narrow a space. The grub foresees 

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